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Sample records for core-ns3 fusion polypeptide

  1. Non-chromatographic Purification of Recombinant Elastin-like Polypeptides and their Fusions with Peptides and Proteins from Escherichia coli

    PubMed Central

    Chilkoti, Ashutosh

    2014-01-01

    Elastin-like polypeptides are repetitive biopolymers that exhibit a lower critical solution temperature phase transition behavior, existing as soluble unimers below a characteristic transition temperature and aggregating into micron-scale coacervates above their transition temperature. The design of elastin-like polypeptides at the genetic level permits precise control of their sequence and length, which dictates their thermal properties. Elastin-like polypeptides are used in a variety of applications including biosensing, tissue engineering, and drug delivery, where the transition temperature and biopolymer architecture of the ELP can be tuned for the specific application of interest. Furthermore, the lower critical solution temperature phase transition behavior of elastin-like polypeptides allows their purification by their thermal response, such that their selective coacervation and resolubilization allows the removal of both soluble and insoluble contaminants following expression in Escherichia coli. This approach can be used for the purification of elastin-like polypeptides alone or as a purification tool for peptide or protein fusions where recombinant peptides or proteins genetically appended to elastin-like polypeptide tags can be purified without chromatography. This protocol describes the purification of elastin-like polypeptides and their peptide or protein fusions and discusses basic characterization techniques to assess the thermal behavior of pure elastin-like polypeptide products. PMID:24961229

  2. Purification of recombinant protein by cold-coacervation of fusion constructs incorporating resilin-inspired polypeptides.

    PubMed

    Lyons, Russell E; Elvin, Christopher M; Taylor, Karin; Lekieffre, Nicolas; Ramshaw, John A M

    2012-12-01

    Polypeptides containing between 4 and 32 repeats of a resilin-inspired sequence AQTPSSYGAP, derived from the mosquito Anopheles gambiae, have been used as tags on recombinant fusion proteins. These repeating polypeptides were inspired by the repeating structures that are found in resilins and sequence-related proteins from various insects. Unexpectedly, an aqueous solution of a recombinant resilin protein displays an upper critical solution temperature (cold-coacervation) when held on ice, leading to a separation into a protein rich phase, typically exceeding 200 mg/mL, and a protein-poor phase. We show that purification of recombinant proteins by cold-coacervation can be performed when engineered as a fusion partner to a resilin-inspired repeat sequence. In this study, we demonstrate the process by the recombinant expression and purification of enhanced Green fluorescent protein (EGFP) in E. coli. This facile purification system can produce high purity, concentrated protein solutions without the need for affinity chromatography or other time-consuming or expensive purification steps, and that it can be used with other bulk purification steps such as low concentration ammonium sulfate precipitation. Protein purification by cold-coacervation also minimizes the exposure of the target protein to enhanced proteolysis at higher temperature.

  3. Optimization of elastin-like polypeptide fusions for expression and purification of recombinant proteins in plants.

    PubMed

    Conley, Andrew J; Joensuu, Jussi J; Jevnikar, Anthony M; Menassa, Rima; Brandle, Jim E

    2009-06-15

    The demand for recombinant proteins for medical and industrial use is expanding rapidly and plants are now recognized as an efficient, inexpensive means of production. Although the accumulation of recombinant proteins in transgenic plants can be low, we have previously demonstrated that fusions with an elastin-like polypeptide (ELP) tag can significantly enhance the production yield of a range of different recombinant proteins in plant leaves. ELPs are biopolymers with a repeating pentapeptide sequence (VGVPG)(n) that are valuable for bioseparation, acting as thermally responsive tags for the non-chromatographic purification of recombinant proteins. To determine the optimal ELP size for the accumulation of recombinant proteins and their subsequent purification, various ELP tags were fused to green fluorescent protein, interleukin-10, erythropoietin and a single chain antibody fragment and then transiently expressed in tobacco leaves. Our results indicated that ELP tags with 30 pentapeptide repeats provided the best compromise between the positive effects of small ELP tags (n = 5-40) on recombinant protein accumulation and the beneficial effects of larger ELP tags (n = 80-160) on recombinant protein recovery during inverse transition cycling (ITC) purification. In addition, the C-terminal orientation of ELP fusion tags produced higher levels of target proteins, relative to N-terminal ELP fusions. Importantly, the ELP tags had no adverse effect on the receptor binding affinity of erythropoietin, demonstrating the inert nature of these tags. The use of ELP fusion tags provides an approach for enhancing the production of recombinant proteins in plants, while simultaneously assisting in their purification.

  4. Evidence that the multifunctional polypeptides of vertebrate and fungal fatty acid synthases have arisen by independent gene fusion events.

    PubMed

    McCarthy, A D; Goldring, J P; Hardie, D G

    1983-10-17

    The enoyl reductase (NADPH binding site) of rabbit mammary fatty acid synthase has been radioactively labelled using pyridoxal phosphate and sodium [3H]borohydride. Using this method we have been able to add this site to the four sites whose location has already been mapped within the multifunctional polypeptide chain of the protein. The results show that the enoyl reductase lies between the 3-oxoacylsynthase and the acyl carrier. This confirms that the active sites occur in a different order on the single multifunctional polypeptide of vertebrate fatty acid synthase and the two multifunctional polypeptides of fungal fatty acid synthase, and suggests that these two systems have arisen by independent gene fusion events.

  5. Protein body formation in stable transgenic tobacco expressing elastin-like polypeptide and hydrophobin fusion proteins

    PubMed Central

    2013-01-01

    Background Plants are recognized as an efficient and inexpensive system to produce valuable recombinant proteins. Two different strategies have been commonly used for the expression of recombinant proteins in plants: transient expression mediated by Agrobacterium; or stable transformation of the plant genome. However, the use of plants as bioreactors still faces two main limitations: low accumulation levels of some recombinant proteins and lack of efficient purification methods. Elastin-like polypeptide (ELP), hydrophobin I (HFBI) and Zera® are three fusion partners found to increase the accumulation levels of recombinant proteins and induce the formation of protein bodies (PBs) in leaves when targeted to the endoplasmic reticulum (ER) in transient expression assays. In this study the effects of ELP and HFBI fusion tags on recombinant protein accumulation levels and PB formation was examined in stable transgenic Nicotiana tabacum. Results The accumulation of recombinant protein and PB formation was evaluated in two cultivars of Nicotiana tabacum transformed with green fluorescent protein (GFP) fused to ELP or HFBI, both targeted and retrieved to the ER. The ELP and HFBI tags increased the accumulation of the recombinant protein and induced the formation of PBs in leaves of stable transgenic plants from both cultivars. Furthermore, these tags induced the formation of PBs in a concentration-dependent manner, where a specific level of recombinant protein accumulation was required for PBs to appear. Moreover, agro-infiltration of plants accumulating low levels of recombinant protein with p19, a suppressor of post-transcriptional gene silencing (PTGS), increased accumulation levels in four independent transgenic lines, suggesting that PTGS might have caused the low accumulation levels in these plants. Conclusion The use of ELP and HFBI tags as fusion partners in stable transgenic plants of tobacco is feasible and promising. In a constitutive environment, these tags

  6. Fusion and fission of molecular assemblies of amphiphilic polypeptides generating small vesicles from nanotubes.

    PubMed

    Watabe, Naoki; Joo Kim, Cheol; Kimura, Shunsaku

    2017-03-01

    Three amphiphilic block polypeptides, (sarcosine)m -b-(l- or d-Leu-Aib)n (L16, D16, D14), having different helical chain lengths or helicity are synthesized. A mixture of L16, D16, and D14 generates vesicles of diameters more than ca. 130 nm by injecting the ethanol solution into water and heating at 90°C for 1 h. On the other hand, when nanotubes composed of L16 and D14 having ca. 50 nm diameter are mixed with nanosheets composed of D16, smaller and homogeneous vesicles of ca. 60 nm diameter are obtained with the heat treatment. The time lapse TEM image analysis of the mixtures revealed some transient structures of nanotubes sticking a nanosheet or a vesicle at the open end of nanotubes. The precise size control of vesicles is therefore attainable by using nanotubes as a structural template regulating the size of vesicles near to the nanotube diameter upon the membrane fission processes.

  7. Elastomeric Polypeptides

    PubMed Central

    van Eldijk, Mark B.; McGann, Christopher L.

    2013-01-01

    Elastomeric polypeptides are very interesting biopolymers and are characterized by rubber-like elasticity, large extensibility before rupture, reversible deformation without loss of energy, and high resilience upon stretching. Their useful properties have motivated their use in a wide variety of materials and biological applications. This chapter focuses on elastin and resilin – two elastomeric biopolymers – and the recombinant polypeptides derived from them (elastin-like polypeptides and resilin-like polypeptides). This chapter also discusses the applications of these recombinant polypeptides in the fields of purification, drug delivery, and tissue engineering. PMID:21826606

  8. Giardiavirus double-stranded RNA genome encodes a capsid polypeptide and a gag-pol-like fusion protein by a translation frameshift.

    PubMed Central

    Wang, A L; Yang, H M; Shen, K A; Wang, C C

    1993-01-01

    Giardiavirus is a small, nonenveloped virus comprising a monopartite double-stranded RNA genome, a major protein of 100 kDa, and a less abundant polypeptide of 190 kDa. It can be isolated from the culture supernatant of Giardia lamblia, a parasitic flagellate in human and other mammals, and efficiently infects other virus-free G. lamblia. A single-stranded copy of the viral RNA can be electroporated into uninfected G. lamblia cells to complete the viral replication cycle. Giardiavirus genomic cDNA of 6100 nt was constructed and its sequence revealed the presence of two large open reading frames that are separated by a -1 frameshift and share an overlap of 220 nt. The 3' open reading frame contains all consensus RNA-dependent RNA polymerase sequence motifs. A heptamer-pseudoknot structure similar to those found at ribosomal slippage sites in retroviruses and yeast killer virus was identified within this overlap. Immunostudies using antisera against synthesized peptides from four regions in the two open reading frames indicated that the 100- and 190-kDa viral proteins share a common domain in the amino-terminal region. But the 190-kDa protein makes a -1 switch of its reading frame beyond the presumed slippage heptamer and is therefore a -1 frameshift fusion protein similar to the gag-pol fusion protein found in retroviruses. Images Fig. 4 Fig. 5 PMID:8378334

  9. Antifungal polypeptides

    DOEpatents

    Altier, Daniel J.; Ellanskaya, Irina; Ellanskaya, legal representative, Natalia; Gilliam, Jacob T.; Hunter-Cevera, Jennie; Presnail, James K.; Schepers, Eric; Simmons, Carl R.; Torok, Tamas; Yalpani, Nasser

    2009-09-15

    The invention relates to antifungal compositions and methods for protecting a plant from a fungal pathogen. Compositions including antifungal polypeptides isolated from a fungal fermentation broth are provided.

  10. Antifungal polypeptides

    DOEpatents

    Altier, Daniel J.; Dahlbacka, Glen; Elleskaya, Irina; Ellanskaya, legal representative; Natalia; Herrmann, Rafael; Hunter-Cevera, Jennie; McCutchen, Billy F.; Presnail, James K.; Rice, Janet A.; Schepers, Eric; Simmons, Carl R.; Torok, Tamas; Yalpani, Nasser

    2010-08-10

    Compositions and methods for protecting a plant from a pathogen, particularly a fungal pathogen, are provided. Compositions include novel amino acid sequences, and variants and fragments thereof, for antipathogenic polypeptides that were isolated from microbial fermentation broths. Nucleic acid molecules comprising nucleotide sequences that encode the antipathogenic polypeptides of the invention are also provided. A method for inducing pathogen resistance in a plant using the nucleotide sequences disclosed herein is further provided. The method comprises introducing into a plant an expression cassette comprising a promoter operably linked to a nucleotide sequence that encodes an antipathogenic polypeptide of the invention. Compositions comprising an antipathogenic polypeptide or a transformed microorganism comprising a nucleic acid of the invention in combination with a carrier and methods of using these compositions to protect a plant from a pathogen are further provided. Transformed plants, plant cells, seeds, and microorganisms comprising a nucleotide sequence that encodes an antipathogenic polypeptide of the invention, or variant or fragment thereof, are also disclosed.

  11. Antifungal polypeptides

    DOEpatents

    Altier, Daniel J.; Dahlbacka, Glen; Ellanskaya, legal representative, Natalia; Herrmann, Rafael; Hunter-Cevera, Jennie; McCutchen, Billy F.; Presnail, James K.; Rice, Janet A.; Schepers, Eric; Simmons, Carl R.; Torok, Tamas; Yalpani, Nasser; Ellanskaya, deceased, Irina

    2007-12-11

    Compositions and methods for protecting a plant from a pathogen, particularly a fungal pathogen, are provided. Compositions include novel amino acid sequences, and variants and fragments thereof, for antipathogenic polypeptides that were isolated from microbial fermentation broths. Nucleic acid molecules comprising nucleotide sequences that encode the antipathogenic polypeptides of the invention are also provided. A method for inducing pathogen resistance in a plant using the nucleotide sequences disclosed herein is further provided. The method comprises introducing into a plant an expression cassette comprising a promoter operably linked to a nucleotide sequence that encodes an antipathogenic polypeptide of the invention. Compositions comprising an antipathogenic polypeptide or a transformed microorganism comprising a nucleic acid of the invention in combination with a carrier and methods of using these compositions to protect a plant from a pathogen are further provided. Transformed plants, plant cells, seeds, and microorganisms comprising a nucleotide sequence that encodes an antipathogenic polypeptide of the invention, or variant or fragment thereof, are also disclosed.

  12. Antifungal polypeptides

    DOEpatents

    Altier, Daniel J.; Dahlbacka, Glen; Elleskaya, Irina; Ellanskaya, legal representative, Natalia; Herrmann, Rafael; Hunter-Cevera, Jennie; McCutchen, Billy F.; Presnail, James K.; Rice, Janet A.; Schepers, Eric; Simmons, Carl R.; Torok, Tamas; Yalpani, Nasser

    2011-04-12

    Compositions and methods for protecting a plant from a pathogen, particularly a fungal pathogen, are provided. Compositions include novel amino acid sequences, and variants and fragments thereof, for antipathogenic polypeptides that were isolated from microbial fermentation broths. Nucleic acid molecules comprising nucleotide sequences that encode the antipathogenic polypeptides of the invention are also provided. A method for inducing pathogen resistance in a plant using the nucleotide sequences disclosed herein is further provided. The method comprises introducing into a plant an expression cassette comprising a promoter operably linked to a nucleotide sequence that encodes an antipathogenic polypeptide of the invention. Compositions comprising an antipathogenic polypeptide or a transformed microorganism comprising a nucleic acid of the invention in combination with a carrier and methods of using these compositions to protect a plant from a pathogen are further provided. Transformed plants, plant cells, seeds, and microorganisms comprising a nucleotide sequence that encodes an antipathogenic polypeptide of the invention, or variant or fragment thereof, are also disclosed.

  13. Antifungal polypeptides

    DOEpatents

    Altier, Daniel J [Granger, IA; Dahlbacka, Glen [Oakland, CA; Ellanskaya, Irina [Kyiv, UA; Ellanskaya, legal representative, Natalia; Herrmann, Rafael [Wilmington, DE; Hunter-Cevera, Jennie [Elliott City, MD; McCutchen, Billy F [College Station, TX; Presnail, James K [Avondale, PA; Rice, Janet A [Wilmington, DE; Schepers, Eric [Port Deposit, MD; Simmons, Carl R [Des Moines, IA; Torok, Tamas [Richmond, CA; Yalpani, Nasser [Johnston, IA

    2012-04-03

    Compositions and methods for protecting a plant from a pathogen, particularly a fungal pathogen, are provided. Compositions include novel amino acid sequences, and variants and fragments thereof, for antipathogenic polypeptides that were isolated from microbial fermentation broths. Nucleic acid molecules comprising nucleotide sequences that encode the antipathogenic polypeptides of the invention are also provided. A method for inducing pathogen resistance in a plant using the nucleotide sequences disclosed herein is further provided. The method comprises introducing into a plant an expression cassette comprising a promoter operably linked to a nucleotide sequence that encodes an antipathogenic polypeptide of the invention. Compositions comprising an antipathogenic polypeptide or a transformed microorganism comprising a nucleic acid of the invention in combination with a carrier and methods of using these compositions to protect a plant from a pathogen are further provided. Transformed plants, plant cells, seeds, and microorganisms comprising a nucleotide sequence that encodes an antipathogenic polypeptide of the invention, or variant or fragment thereof, are also disclosed.

  14. Fusion

    NASA Astrophysics Data System (ADS)

    Herman, Robin

    1990-10-01

    The book abounds with fascinating anecdotes about fusion's rocky path: the spurious claim by Argentine dictator Juan Peron in 1951 that his country had built a working fusion reactor, the rush by the United States to drop secrecy and publicize its fusion work as a propaganda offensive after the Russian success with Sputnik; the fortune Penthouse magazine publisher Bob Guccione sank into an unconventional fusion device, the skepticism that met an assertion by two University of Utah chemists in 1989 that they had created "cold fusion" in a bottle. Aimed at a general audience, the book describes the scientific basis of controlled fusion--the fusing of atomic nuclei, under conditions hotter than the sun, to release energy. Using personal recollections of scientists involved, it traces the history of this little-known international race that began during the Cold War in secret laboratories in the United States, Great Britain and the Soviet Union, and evolved into an astonishingly open collaboration between East and West.

  15. Targeted polypeptide degradation

    DOEpatents

    Church, George M.; Janse, Daniel M.

    2008-05-13

    This invention pertains to compositions, methods, cells and organisms useful for selectively localizing polypeptides to the proteasome for degradation. Therapeutic methods and pharmaceutical compositions for treating disorders associated with the expression and/or activity of a polypeptide by targeting these polypeptides for degradation, as well as methods for targeting therapeutic polypeptides for degradation and/or activating therapeutic polypeptides by degradation are provided. The invention provides methods for identifying compounds that mediate proteasome localization and/or polypeptide degradation. The invention also provides research tools for the study of protein function.

  16. The uptake machinery of clostridial actin ADP-ribosylating toxins--a cell delivery system for fusion proteins and polypeptide drugs.

    PubMed

    Barth, Holger; Blöcker, Dagmar; Aktories, Klaus

    2002-12-01

    Several bacterial protein toxins, including Clostridium botulinum C2 toxin, Clostridum perfringens iota toxin, Clostridium difficile ADP-ribosyltransferase, and the Bacillus-produced vegetative insecticidal proteins, target the cytoskeleton by ADP-ribosylation of actin. All these toxins are binary in structure and consist of an enzyme component, possessing ADP-ribosyltransferase activity and a separated binding and translocation component, which is involved in the delivery of the enzyme component into the cell. The toxins are not only important virulence factors but also cell biological tools to study the function of the actin cytoskeleton. Moreover, the binary toxins turned out to be effective transporter systems for the delivery of specific fusion toxins (e.g., Rho-ADP-ribosylating C3 exoenzyme) into cells. The present review describes the biological functions of the toxins, focuses on recent studies on the uptake and delivery mechanism and discusses the usage as a drug delivery system.

  17. Methods of increasing secretion of polypeptides having biological activity

    SciTech Connect

    Merino, Sandra

    2013-10-01

    The present invention relates to methods for producing a secreted polypeptide having biological activity, comprising: (a) transforming a fungal host cell with a fusion protein construct encoding a fusion protein, which comprises: (i) a first polynucleotide encoding a signal peptide; (ii) a second polynucleotide encoding at least a catalytic domain of an endoglucanase or a portion thereof; and (iii) a third polynucleotide encoding at least a catalytic domain of a polypeptide having biological activity; wherein the signal peptide and at least the catalytic domain of the endoglucanase increases secretion of the polypeptide having biological activity compared to the absence of at least the catalytic domain of the endoglucanase; (b) cultivating the transformed fungal host cell under conditions suitable for production of the fusion protein; and (c) recovering the fusion protein, a component thereof, or a combination thereof, having biological activity, from the cultivation medium.

  18. Methods of increasing secretion of polypeptides having biological activity

    DOEpatents

    Merino, Sandra

    2014-10-28

    The present invention relates to methods for producing a secreted polypeptide having biological activity, comprising: (a) transforming a fungal host cell with a fusion protein construct encoding a fusion protein, which comprises: (i) a first polynucleotide encoding a signal peptide; (ii) a second polynucleotide encoding at least a catalytic domain of an endoglucanase or a portion thereof; and (iii) a third polynucleotide encoding at least a catalytic domain of a polypeptide having biological activity; wherein the signal peptide and at least the catalytic domain of the endoglucanase increases secretion of the polypeptide having biological activity compared to the absence of at least the catalytic domain of the endoglucanase; (b) cultivating the transformed fungal host cell under conditions suitable for production of the fusion protein; and (c) recovering the fusion protein, a component thereof, or a combination thereof, having biological activity, from the cultivation medium.

  19. Methods of increasing secretion of polypeptides having biological activity

    DOEpatents

    Merino, Sandra

    2014-05-27

    The present invention relates to methods for producing a secreted polypeptide having biological activity, comprising: (a) transforming a fungal host cell with a fusion protein construct encoding a fusion protein, which comprises: (i) a first polynucleotide encoding a signal peptide; (ii) a second polynucleotide encoding at least a catalytic domain of an endoglucanase or a portion thereof; and (iii) a third polynucleotide encoding at least a catalytic domain of a polypeptide having biological activity; wherein the signal peptide and at least the catalytic domain of the endoglucanase increases secretion of the polypeptide having biological activity compared to the absence of at least the catalytic domain of the endoglucanase; (b) cultivating the transformed fungal host cell under conditions suitable for production of the fusion protein; and (c) recovering the fusion protein, a component thereof, or a combination thereof, having biological activity, from the cultivation medium.

  20. Methods of increasing secretion of polypeptides having biological activity

    SciTech Connect

    Merino, Sandra

    2015-04-14

    The present invention relates to methods for producing a secreted polypeptide having biological activity, comprising: (a) transforming a fungal host cell with a fusion protein construct encoding a fusion protein, which comprises: (i) a first polynucleotide encoding a signal peptide; (ii) a second polynucleotide encoding at least a catalytic domain of an endoglucanase or a portion thereof; and (iii) a third polynucleotide encoding at least a catalytic domain of a polypeptide having biological activity; wherein the signal peptide and at least the catalytic domain of the endoglucanase increases secretion of the polypeptide having biological activity compared to the absence of at least the catalytic domain of the endoglucanase; (b) cultivating the transformed fungal host cell under conditions suitable for production of the fusion protein; and (c) recovering the fusion protein, a component thereof, or a combination thereof, having biological activity, from the cultivation medium.

  1. Selective posttranslational modification of phage-displayed polypeptides

    SciTech Connect

    Tsao, Meng-Lin; Tian, Feng; Schultz, Peter

    2013-11-19

    The invention relates to posttranslational modification of phage-displayed polypeptides. These displayed polypeptides comprise at least one unnatural amino acid, e.g., an aryl-azide amino acid such as p-azido-L-phenylalanine, or an alkynyl-amino acid such as para-propargyloxyphenylalanine, which are incorporated into the phage-displayed fusion polypeptide at a selected position by using an in vivo orthogonal translation system comprising a suitable orthogonal aminoacyl-tRNA synthetase and a suitable orthogonal tRNA species. These unnatural amino acids advantageously provide targets for posttranslational modifications such as azide-alkyne [3+2] cycloaddition reactions and Staudinger modifications.

  2. Selective posttranslational modification of phage-displayed polypeptides

    SciTech Connect

    Tsao, Meng-Lin; Tian, Feng; Schultz, Peter

    2013-02-05

    The invention relates to posttranslational modification of phage-displayed polypeptides. These displayed polypeptides comprise at least one unnatural amino acid, e.g., an aryl-azide amino acid such as p-azido-L-phenylalanine, or an alkynyl-amino acid such as para-propargyloxyphenylalanine, which are incorporated into the phage-displayed fusion polypeptide at a selected position by using an in vivo orthogonal translation system comprising a suitable orthogonal aminoacyl-tRNA synthetase and a suitable orthogonal tRNA species. These unnatural amino acids advantageously provide targets for posttranslational modifications such as azide-alkyne [3+2]cycloaddition reactions and Staudinger modifications.

  3. Directed evolution methods for improving polypeptide folding and solubility and superfolder fluorescent proteins generated thereby

    DOEpatents

    Waldo, Geoffrey S.

    2007-09-18

    The current invention provides methods of improving folding of polypeptides using a poorly folding domain as a component of a fusion protein comprising the poorly folding domain and a polypeptide of interest to be improved. The invention also provides novel green fluorescent proteins (GFPs) and red fluorescent proteins that have enhanced folding properties.

  4. Organic Anion Transporting Polypeptides

    PubMed Central

    Stieger, Bruno; Hagenbuch, Bruno

    2013-01-01

    Organic anion transporting polypeptides or OATPs are central transporters in the disposition of drugs and other xenobiotics. In addition, they mediate transport of a wide variety of endogenous substrates. The critical role of OATPs in drug disposition has spurred research both in academia and in the pharmaceutical industry. Translational aspects with clinical questions are the focus in academia, while the pharmaceutical industry tries to define and understand the role these transporters play in pharmacotherapy. The present overview summarizes our knowledge on the interaction of food constituents with OATPs, and on the OATP transport mechanisms. Further, it gives an update on the available information on the structure-function relationship of the OATPs, and finally, covers the transcriptional and posttranscriptional regulation of OATPs. PMID:24745984

  5. Methods for producing secreted polypeptides

    SciTech Connect

    Maiyuran, Suchindra; Fidantsef, Ana; Brody, Howard

    2008-07-01

    The present invention relates to methods for producing a polypeptide, comprising: (a) cultivating a fungal host cell in a medium conducive for the production of the polypeptide, wherein the fungal host cell comprises a nucleic acid construct comprising a first nucleotide sequence encoding a signal peptide operably linked to a second nucleotide sequence encoding the polypeptide, wherein the first nucleotide sequence is foreign to the second nucleotide sequence and the 3' end of the first nucleotide sequence is immediately upstream of the initiator codon of the second nucleotide sequence. The present invention also relates to the isolated signal peptide sequences and to constructs, vectors, and fungal host cells comprising the signal peptide sequences operably linked to nucleotide sequences encoding polypeptides.

  6. Methods for producing secreted polypeptides

    SciTech Connect

    Maiyuran, Suchindra; Fidantsef, Ana; Brody, Howard

    2013-07-30

    The present invention relates to methods for producing a polypeptide, comprising: (a) cultivating a fungal host cell in a medium conducive for the production of the polypeptide, wherein the fungal host cell comprises a nucleic acid construct comprising a first nucleotide sequence encoding a signal peptide operably linked to a second nucleotide sequence encoding the polypeptide, wherein the first nucleotide sequence is foreign to the second nucleotide sequence and the 3' end of the first nucleotide sequence is immediately upstream of the initiator codon of the second nucleotide sequence. The present invention also relates to the isolated signal peptide sequences and to constructs, vectors, and fungal host cells comprising the signal peptide sequences operably linked to nucleotide sequences encoding polypeptides.

  7. Hydrogenase polypeptide and methods of use

    DOEpatents

    Adams, Michael W.W.; Hopkins, Robert C.; Jenney, JR, Francis E.; Sun, Junsong

    2016-02-02

    Provided herein are polypeptides having hydrogenase activity. The polypeptide may be multimeric, and may have hydrogenase activity of at least 0.05 micromoles H.sub.2 produced min.sup.-1 mg protein.sup.-1. Also provided herein are polynucleotides encoding the polypeptides, genetically modified microbes that include polynucleotides encoding one or more subunits of the multimeric polypeptide, and methods for making and using the polypeptides.

  8. Methods for using polypeptides having cellobiohydrolase activity

    DOEpatents

    Morant, Marc D; Harris, Paul

    2016-08-23

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  9. Simple bioseparations using self-cleaving elastin-like polypeptide tags.

    PubMed

    Banki, Mahmoud Reza; Feng, Liang; Wood, David W

    2005-09-01

    We introduce a new method for the purification of recombinant proteins expressed in Escherichia coli using self-cleaving elastin-like polypeptide (ELP) fusion tags without the need for affinity chromatography or proteolytic tag removal. Using this method we obtained high purity, activity and reasonable yields for ten diverse target proteins.

  10. Nano polypeptide particles reinforced polymer composite fibers.

    PubMed

    Li, Jiashen; Li, Yi; Zhang, Jing; Li, Gang; Liu, Xuan; Li, Zhi; Liu, Xuqing; Han, Yanxia; Zhao, Zheng

    2015-02-25

    Because of the intensified competition of land resources for growing food and natural textile fibers, there is an urgent need to reuse and recycle the consumed/wasted natural fibers as regenerated green materials. Although polypeptide was extracted from wool by alkaline hydrolysis, the size of the polypeptide fragments could be reduced to nanoscale. The wool polypeptide particles were fragile and could be crushed down to nano size again and dispersed evenly among polymer matrix under melt extrusion condition. The nano polypeptide particles could reinforce antiultraviolet capability, moisture regain, and mechanical properties of the polymer-polypeptide composite fibers.

  11. Polypeptide toxins from animal venoms.

    PubMed

    Kozlov, Sergey A

    2007-01-01

    In the course of evolution, venomous animals developed highly specialized venomous systems that provided for drastic increase in hunting and defense efficiency. Venoms of a vast number of animal species represent complex mixtures of compounds such as ions, biogenic amines, polyamines, polypeptide neurotoxins, cytolytic peptides, enzymes, etc. that exert different functions. Natural toxins are sequentially variable molecules that are very stable structurally and produce pronounced biological effects on molecular targets. High activity made them very attractive in terms of novel structure discovery and characterization. In the present review we draw attention to the structure of polypeptide molecules preferably in the 2-12 kDa molecular mass range produced by various venomous animals that were published in patent literature. The structures were reviewed on the basis of functional relation to molecular targets. We also compared the sequence information from patents with Uniprot and other protein databanks to define structures that were patented but missing from the public databases.

  12. Elastomeric polypeptide-based biomaterials

    PubMed Central

    Li, Linqing; Charati, Manoj B.; Kiick, Kristi L.

    2011-01-01

    Elastomeric proteins are characterized by their large extensibility before rupture, reversible deformation without loss of energy, and high resilience upon stretching. Motivated by their unique mechanical properties, there has been tremendous research in understanding and manipulating elastomeric polypeptides, with most work conducted on the elastins but more recent work on an expanded set of polypeptide elastomers. Facilitated by biosynthetic strategies, it has been possible to manipulate the physical properties, conformation, and mechanical properties of these materials. Detailed understanding of the roles and organization of the natural structural proteins has permitted the design of elastomeric materials with engineered properties, and has thus expanded the scope of applications from elucidation of the mechanisms of elasticity to the development of advanced drug delivery systems and tissue engineering substrates. PMID:21637725

  13. Phycobilisome structure of porphyridium cruentum: polypeptide composition

    SciTech Connect

    Redlinger, T.; Gantt, E.

    1981-01-01

    Purified phycobilisomes of porphyridium cruentum were solubilized in sodium dodecyl sulfate and resolved by sodium dodecyl sulfate-acrylamide gel electrophoresis into nine colored and nine colorless polypeptides. The colored polypeptides accounted for about 84% of the total stainable protein, and the colorless polypeptides accounted for the remaining 16%. Five of the colored polypeptides ranging in molecular weight from 13,300 to 19,500 were identified as the ..cap alpha.. and ..beta.. subunits of allophycocyanin, R-phycocyanin, and phycoerythrin. Three others (29,000-30,500) were orange and are probably related to the ..gamma.. subunit of phycoerythrin. Sequential dissociation of phycobilisomes, and analysis of the polypeptides in each fraction, revealed the association of a 32,500 molecular weight colorless polypeptide with a phycoerythrin fraction. The remaining eight colorless polypeptides were in the core fraction of the phycobilisome, which also was enriched in allophycocyanin.

  14. Electrospun Synthetic Polypeptide Nanofibrous Biomaterials

    NASA Astrophysics Data System (ADS)

    Khadka, Dhan; Haynie, Donald

    2011-03-01

    Water-insoluble nanofiber mats of synthetic polypeptides of defined composition have been prepared from fibers electrospun from aqueous solution in the absence of organic co-solvents. 20-50 kDa poly(L-glutamate, L-tyrosine) 4:1 (PLGY) but not 15-50 kDa or 50-100 kDa poly(L-glutamate) was spinnable at 20-55% (w/v) polymer in water. Applied voltage and needle-collector distance were crucial for spinnability. Attractive fibers were obtained at 50% polymer. Fiber diameter and mat morphology have been characterized by electron microscopy. Exposure of spun fiber mats to 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC), which reacts with carboxylate, decreased fiber solubility. Fluorescein-conjugated poly(L-lysine) (FITC-PLL) but not the fluorophore alone was able bind PLGY fiber mats electrostatically, judging by fluorescence microscopy. Key advances of this work are the avoidance of an animal source of peptides and of an inorganic co-solvent to achieve polypeptide spinnability. Polypeptide fiber mats are a promising type of nano-structured biomaterial for applications in biomedicine and biotechnology.

  15. Polypeptide having cellobiohydrolase activity and uses thereof

    DOEpatents

    Sagt, Cornelis Maria Jacobus; Schooneveld-Bergmans, Margot Elisabeth Francoise; Roubos, Johannes Andries; Los, Alrik Pieter

    2015-09-15

    The invention relates to a polypeptide comprising the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 93% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 93% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional polypeptide and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  16. Polypeptide having swollenin activity and uses thereof

    SciTech Connect

    Schoonneveld-Bergmans, Margot Elizabeth Francoise; Heijne, Wilbert Herman Marie; Vlasie, Monica D; Damveld, Robbertus Antonius

    2015-11-04

    The invention relates to a polypeptide comprising the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 73% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 73% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional polypeptide and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  17. A polypeptide from shark troponin I can inhibit angiogenesis and tumor growth.

    PubMed

    Xie, Qiuling; Yao, Sheng; Chen, Xiaojia; Xu, Lihui; Peng, Wendan; Zhang, Ling; Zhang, Qihao; Liang, Xu-Fang; Hong, An

    2012-02-01

    The shark troponin I gene (TnI) was found for the first time in this study to inhibit endothelial cell proliferation and angiogenesis. This shark TnI had 68.9% amino acid homology with human TnI, whereas the polypeptide from Lys91 to Leu123, which is thought to be the active site of TnI, had 78.8% homology with the corresponding fragment of human TnI. However, the polypeptide of shark had higher activity to inhibit the proliferation of HUVEC and tumor cell lines than that of human TnI. To investigate the anti-angiogenesis and anti-tumor effect of the shark TnI polypeptide, the DNA sequence of polypeptide (Lys91-Leu123) of white-spot catshark TnI(psTnI) was cloned and fused with the His-SUMO cDNA, followed by expression in Escherichia coli. After its purification by Ni(2+) affinity chromatography, the fusion His-SUMO-psTnI protein was digested with the SUMO enzyme to release psTnI. The inhibitory ability of this recombinant shark TnI polypeptide for angiogenesis was confirmed by chicken embryo allantoic membrane (CAM) test and IHC analysis. It was also found by breast carcinoma xenograft study in Balb/c mice that this polypeptide could inhibit tumor growth in vivo.

  18. Bodian's Silver Method Stains Neurofilament Polypeptides

    NASA Astrophysics Data System (ADS)

    Gambetti, P.; Autilio-Gambetti, L.; Papasozomenos, S. Ch.

    1981-09-01

    Bodian's silver method was used to stain polypeptides of rat spinal cord or peripheral nerve separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The bands corresponding to the three polypeptide subunits of the neurofilaments were intensely impregnated. Two other polypeptides were stained inconsistently and less intensely. The tubulin band was stained weakly or not at all; other polypeptides, including glial fibrillary acidic protein, actin, and vimentin, remained unstained. This novel application of Bodian's method provides indirect proof that neurofilaments are the neuronal subcellular structure stained by the technique.

  19. Methods for engineering polypeptide variants via somatic hypermutation and polypeptide made thereby

    DOEpatents

    Tsien, Roger Y; Wang, Lei

    2015-01-13

    Methods using somatic hypermutation (SHM) for producing polypeptide and nucleic acid variants, and nucleic acids encoding such polypeptide variants are disclosed. Such variants may have desired properties. Also disclosed are novel polypeptides, such as improved fluorescent proteins, produced by the novel methods, and nucleic acids, vectors, and host cells comprising such vectors.

  20. Ordered biological nanostructures formed from chaperonin polypeptides

    NASA Technical Reports Server (NTRS)

    Trent, Jonathan D. (Inventor); McMillan, R. Andrew (Inventor); Kagawa, Hiromi (Inventor); Paavola, Chad D. (Inventor)

    2010-01-01

    The following application relates to nanotemplates, nanostructures, nanoarrays and nanodevices formed from wild-type and mutated chaperonin polypeptides, methods of producing such compositions, methods of using such compositions and particular chaperonin polypeptides that can be utilized in producing such compositions.

  1. Hybrid polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    SciTech Connect

    Liu, Ye; Shaghasi, Tarana

    2016-11-01

    The present invention provides hybrid polypeptides having cellobiohydrolase activity. The present invention also provides polynucleotides encoding the hybrid polypeptides; nucleic acid constructs, vectors and host cells comprising the polynucleotides; and processes of using the hybrid polypeptides.

  2. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    SciTech Connect

    Zhang, Yu; Duan, Junxin; Tang, Lan; Wu, Wenping

    2015-06-09

    Provided are isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. Also provided are nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  3. Polypeptides having endoglucanase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2015-02-10

    The present invention relates to isolated polypeptides having endoglucanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  4. Polypeptides having endoglucanase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2015-11-17

    The present invention relates to isolated polypeptides having endoglucanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  5. Polypeptides having xylanase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2015-10-27

    The present invention relates to isolated polypeptides having xylanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  6. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2015-11-17

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  7. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2015-03-31

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  8. Isolation of Polypeptide Sample and Measurement of Its Concentration.

    ERIC Educational Resources Information Center

    Beanan, Maureen J.

    2000-01-01

    Introduces a laboratory experiment that isolates a bacterial polypeptide sample and measures the concentration of polypeptides in the sample. Uses Escherichia coli strain MM294 and performs a bio-rad assay to determine the concentration of polypeptides. (YDS)

  9. Polypeptides having cellobiohydrolase activitiy and polynucleotides encoding same

    SciTech Connect

    Liu, Ye; Tang, Lan; Duan, Junxin

    2015-12-15

    The present invention provides isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also provides nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  10. Polypeptides having endoglucanase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2014-07-15

    The present invention relates to isolated polypeptides having endoglucanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  11. Polypeptides having endoglucanse activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2014-07-08

    The present invention relates to isolated polypeptides having endoglucanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  12. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2014-06-24

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  13. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2014-07-15

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  14. Polypeptides having xylanase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2014-06-24

    The present invention relates to isolated polypeptides having xylanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  15. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2014-07-08

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  16. Polypeptides having xylanase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2014-10-14

    The present invention relates to isolated polypeptides having xylanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  17. Polypeptides having xylanase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2015-08-18

    The present invention relates to isolated polypeptides having xylanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  18. Polypeptides having endoglucanase activity and polynucleotides encoding same

    DOEpatents

    Liu, Ye; Duan, Junxin; Tang, Lan

    2015-09-22

    The present invention provides isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. The invention also provides nucleic acid constructs, vectors, and host cell comprising the polynucleotides as well as methods of producing and using the polypeptides.

  19. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    SciTech Connect

    Spodsberg, Nikolaj

    2016-12-13

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  20. Switching of filamin polypeptides during myogenesis in vitro

    PubMed Central

    1983-01-01

    During chicken skeletal myogenesis in vitro, the actin-binding protein filamin is present at first in association with actin filament bundles both in myoblasts and in myotubes early after fusion. Later in mature myotubes it is found in association with myofibril Z disks. These two associations of filamin are separated by a period of several days, during which the protein is absent from the cytoplasm of differentiating myotubes (Gomer, R., and E. Lazarides, 1981, Cell, 23:524-532). To characterize the two classes of filamin polypeptides we have compared, by two-dimensional peptide mapping, 125I-labeled filamin immunoprecipitated from myoblasts and fibroblasts to filamin immunoprecipitated from mature myotubes and adult skeletal myofibrils. Myoblast filamin is highly homologous to fibroblast and purified chicken gizzard filamins. Mature myotube and adult myofibril filamins are highly homologous but exhibit extensive peptide differences with respect to the other three classes of filamin. Comparison of peptide maps from immunoprecipitated 35S-methionine-labeled filamins also shows that fibroblast and myoblast filamins are highly homologous but show substantial peptide differences with respect to mature myotube filamin. Filamins from both mature myotubes and skeletal myofibrils exhibit a slightly higher electrophoretic mobility than gizzard, fibroblast, and myoblast filamins. Short pulse-labeling studies show that mature myotube filamin is synthesized as a lower molecular weight variant and is not derived from a higher molecular weight precursor. These results suggest that myoblast and mature myotube filamins are distinct gene products and that during skeletal myogenesis in vitro one class of filamin polypeptides is replaced by a new class of filamin polypeptides, and that the latter is maintained into adulthood. PMID:6833359

  1. cDNA encoding a polypeptide including a hevein sequence

    DOEpatents

    Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

    1995-03-21

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1,018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli. 11 figures.

  2. cDNA encoding a polypeptide including a hevein sequence

    DOEpatents

    Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

    1999-05-04

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli. 12 figs.

  3. CDNA encoding a polypeptide including a hevein sequence

    DOEpatents

    Raikhel, Natasha V.; Broekaert, Willem F.; Chua, Nam-Hai; Kush, Anil

    1995-03-21

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  4. cDNA encoding a polypeptide including a hevein sequence

    DOEpatents

    Raikhel, Natasha V.; Broekaert, Willem F.; Chua, Nam-Hai; Kush, Anil

    1999-05-04

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  5. cDNA encoding a polypeptide including a hevein sequence

    SciTech Connect

    Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

    2000-07-04

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  6. Restriction/modification polypeptides, polynucleotides, and methods

    DOEpatents

    Westpheling, Janet; Chung, DaeHwan; Huddleston, Jennifer; Farkas, Joel A

    2015-02-24

    The present invention relates to the discovery of a novel restriction/modification system in Caldicellulosiruptor bescii. The discovered restriction enzyme is a HaeIII-like restriction enzyme that possesses a thermophilic activity profile. The restriction/modification system also includes a methyltransferase, M.CbeI, that methylates at least one cytosine residue in the CbeI recognition sequence to m.sup.4C. Thus, the invention provides, in various aspects, isolated CbeI or M.CbeI polypeptides, or biologically active fragments thereof; isolated polynucleotides that encode the CbeI or M.CbeI polypeptides or biologically active fragments thereof, including expression vectors that include such polynucleotide sequences; methods of digesting DNA using a CbeI polypeptide; methods of treating a DNA molecule using a M.CbeI polypeptide; and methods of transforming a Caldicellulosiruptor cell.

  7. Polypeptides of the Maize Amyloplast Stroma1

    PubMed Central

    Yu, Ying; He Mu, Helen; Mu-Forster, Chen; Wasserman, Bruce P.

    1998-01-01

    In the developing endosperm of monocotyledonous plants, starch granules are synthesized and deposited within the amyloplast. A soluble stromal fraction was isolated from amyloplasts of immature maize (Zea mays L.) endosperm and analyzed for enzyme activities and polypeptide content. Specific activities of starch synthase and starch-branching enzyme (SBE), but not the cytosolic marker alcohol dehydrogenase, were strongly enhanced in soluble amyloplast stromal fractions relative to soluble extracts obtained from homogenized kernels or endosperms. Immunoblot analysis demonstrated that starch synthase I, SBEIIb, and sugary1, the putative starch-debranching enzyme, were each highly enriched in the amyloplast stroma, providing direct evidence for the localization of starch-biosynthetic enzymes within this compartment. Analysis of maize mutants shows the deficiency of the 85-kD SBEIIb polypeptide in the stroma of amylose extender cultivars and that the dull mutant lacks a >220-kD stromal polypeptide. The stromal fraction is distinguished by differential enrichment of a characteristic group of previously undocumented polypeptides. N-terminal sequence analysis revealed that an abundant 81-kD stromal polypeptide is a member of the Hsp70 family of stress-related proteins. Moreover, the 81-kD stromal polypeptide is strongly recognized by antibodies specific for an Hsp70 of the chloroplast stroma. These findings are discussed in light of implications for the correct folding and assembly of soluble, partially soluble, and granule-bound starch-biosynthetic enzymes during import into the amyloplast. PMID:9536063

  8. Polypeptide having an amino acid replaced with N-benzylglycine

    DOEpatents

    Mitchell, Alexander R.; Young, Janis D.

    1996-01-01

    The present invention relates to one or more polypeptides having useful biological activity in a mammal, which comprise: a polypeptide related to bradykinin of four to ten amino acid residues wherein one or more specific amino acids in the polypeptide chain are replaced with achiral N-benzylglycine. These polypeptide analogues have useful potent agonist or antagonist pharmacological properties depending upon the structure. A preferred polypeptide is (N-benzylglycine.sup.7)-bradykinin.

  9. Carbohydrate degrading polypeptide and uses thereof

    DOEpatents

    Sagt, Cornelis Maria Jacobus; Schooneveld-Bergmans, Margot Elisabeth Francoise; Roubos, Johannes Andries; Los, Alrik Pieter

    2015-10-20

    The invention relates to a polypeptide having carbohydrate material degrading activity which comprises the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1 or SEQ ID NO: 4, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 96% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 96% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional protein and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  10. Spinal Fusion

    MedlinePlus

    ... concept of fusion is similar to that of welding in industry. Spinal fusion surgery, however, does not ... bone taken from the patient has a long history of use and results in predictable healing. Autograft ...

  11. Maize mitochondria synthesize organ-specific polypeptides

    SciTech Connect

    Newton, K.J.; Walbot, V.

    1985-10-01

    The authors detected both quantitative and qualitative organ-specific differences in the total protein composition of mitochondria of maize. Labeling of isolated mitochondria from each organ demonstrated that a few protein differences are due to changes in the polypeptides synthesized by the organelle. The synthesis of developmental stage-specific mitochondrial polypeptides was found in the scutella of developing and germinating kernels. The approximately 13-kDa polypeptide synthesized by mitochondria from seedlings of the Texas (T) male-sterile cytoplasm was shown to be constitutively expressed in all organs of line B37T tested. Methomyl, an insecticide known to inhibit the growth of T sterile plants, was shown to be an effective inhibitor of protein synthesis in mitochondria from T plants.

  12. Biosynthesis and characterization of a non-repetitive polypeptide derived from silk fibroin heavy chain.

    PubMed

    Yang, Gaoqiang; Wu, Mingyang; Yi, Honggen; Wang, Jiannan

    2016-02-01

    Silk fibroin heavy chain is the major protein component of Bombyx mori silk fibroin and is composed of 12 repetitive and 11 non-repetitive regions, with the non-repetitive domain consisting of a hydrophilic polypeptide chain. In order to determine the biomedical function of the non-repetitive domain or potentially use it to modify hydrophobic biomaterials, high-purity isolation is necessary. Previously, we cloned and extended a gene motif (f(1)) encoding the non-repetitive domain. Here, this motif and its multimers are inserted into a glutathione S-transferase (GST)-tagged fusion-protein expression vector. Motif f(1) and multimers f(4) and f(8) were expressed in Escherichia coli BL21 cells following isopropyl β-D-1-thiogalactopyranoside induction, purified by GST-affinity chromatography, and single bands of purified fusion proteins GST-F(1), GST-F(4), and GST-F(8), were visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Target polypeptides F(1), F(4), and F(8), were cleaved clearly from the GST-fusion tag following thrombin digestion. Mass spectrometry results indicate that the molecular weights associated with fusion proteins GST-F(1), GST-F(4), and GST-F(8) are 31.5, 43.8, and 59.0kDa, respectively, and with the cleaved polypeptides F(1), F(4), and F(8) are 4.8, 16.8, and 32.8kDa, respectively. The F(1), F(4), and F(8) polypeptide chains are negatively charged with isoelectric points (pI) of 3.3, 3.2, and 3.0, respectively. The molecular weight and pI values of the polypeptide chains are consistent with the predicted values and the amino acid compositions similar to predicted sequences. FTIR and CD results show the molecular conformation of F(1) was mainly random coil, and more stable α-helix structure formed in longer molecular chain.

  13. Peppytides: Interactive Models of Polypeptide Chains

    SciTech Connect

    Zuckermann, Ron; Chakraborty, Promita; Derisi, Joe

    2014-01-21

    Peppytides are scaled, 3D-printed models of polypeptide chains that can be folded into accurate protein structures. Designed and created by Berkeley Lab Researcher, Promita Chakraborty, and Berkeley Lab Senior Scientist, Dr. Ron Zuckermann, Peppytides are accurate physical models of polypeptide chains that anyone can interact with and fold intro various protein structures - proving to be a great educational tool, resulting in a deeper understanding of these fascinating structures and how they function. Build your own Peppytide model and learn about how nature's machines fold into their intricate architectures!

  14. Peppytides: Interactive Models of Polypeptide Chains

    ScienceCinema

    Zuckermann, Ron; Chakraborty, Promita; Derisi, Joe

    2016-07-12

    Peppytides are scaled, 3D-printed models of polypeptide chains that can be folded into accurate protein structures. Designed and created by Berkeley Lab Researcher, Promita Chakraborty, and Berkeley Lab Senior Scientist, Dr. Ron Zuckermann, Peppytides are accurate physical models of polypeptide chains that anyone can interact with and fold intro various protein structures - proving to be a great educational tool, resulting in a deeper understanding of these fascinating structures and how they function. Build your own Peppytide model and learn about how nature's machines fold into their intricate architectures!

  15. Radioscapholunate Fusions

    PubMed Central

    McGuire, Duncan Thomas; Bain, Gregory Ian

    2012-01-01

    Radiocarpal fusions are performed for a variety of indications, most commonly for debilitating painful arthritis. The goal of a wrist fusion is to fuse the painful, diseased joints and to preserve motion through the healthy joints. Depending on the extent of the disease process, radiocarpal fusions may take the form of radiolunate, radioscapholunate, or total wrist fusions. Surgical techniques and instrumentation have advanced over the last few decades, and consequently the functional outcomes have improved and complications decreased. Techniques for partial carpal fusions have improved and now include distal scaphoid and triquetrum excision, which improves range of motion and fusion rates. In this article we discuss the various surgical techniques and fixation methods available and review the corresponding evidence in the literature. The authors' preferred surgical technique of radioscapholunate fusion with distal scaphoid and triquetrum excision is outlined. New implants and new concepts are also discussed. PMID:24179717

  16. Polypeptides having cellulolytic enhancing activity and nucleic acids encoding same

    SciTech Connect

    Brown, Kimberly; Harris, Paul; Zaretsky, Elizabeth; Re, Edward; Vlasenko, Elena; McFarland, Keith; Lopez de Leon, Alfredo

    2016-08-09

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  17. Polypeptides having cellulolytic enhancing activity and nucleic acids encoding same

    SciTech Connect

    Brown, Kimberly; Harris, Paul; Zaretsky, Elizabeth; Re, Edward; Vlasenko, Elena; McFarland, Keith; Lopez de Leon, Alfredo

    2014-09-30

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  18. Polypeptides having xylanase activity and polynucleotides encoding same

    SciTech Connect

    Tang, Lan; Liu, Ye; Duan, Junxin; Hanshu, Ding

    2012-10-30

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  19. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    SciTech Connect

    Morant, Marc

    2014-01-14

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase, or beta-glucosidase activity and isolated polynucleotides encoding polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  20. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    SciTech Connect

    Zhang, Yu; Duan, Junxin; Tang, Lan; Wu, Wenping

    2016-06-14

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  1. Polypeptides having xylanase activity and polynucleotides encoding same

    SciTech Connect

    Lopez de Leon, Alfredo; Rey, Michael

    2016-05-31

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  2. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    DOEpatents

    Zhang, Yu; Duan, Junxin; Tang, Lan; Wu, Wenping

    2016-11-22

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  3. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    DOEpatents

    Liu, Ye; Harris, Paul; Tang, Lan; Wu, Wenping

    2013-11-19

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  4. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    DOEpatents

    Maiyuran, Suchindra; Kramer, Randall; Harris, Paul

    2014-10-21

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  5. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    SciTech Connect

    Schnorr, Kirk; Kramer, Randall

    2016-04-05

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  6. Polypeptides having xylanase activity and polynucleotides encoding same

    DOEpatents

    Lopez de Leon, Alfredo; Rey, Michael

    2010-12-14

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  7. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    DOEpatents

    Dotson, William D.; Greenier, Jennifer; Ding, Hanshu

    2007-09-18

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated nucleic acids encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the nucleic acids as well as methods for producing and using the polypeptides.

  8. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    DOEpatents

    Lopez de Leon, Alfredo; Ding, Hanshu; Brown, Kimberly

    2011-10-25

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  9. Polypeptides having endoglucanase activity and polynucleotides encoding same

    DOEpatents

    Harris, Paul [Carnation, WA; Lopez de Leon, Alfredo [Davis, CA; Rey, Micheal [Davis, CA; Ding, Hanshu [Davis, CA; Vlasenko, Elena [Davis, CA

    2012-02-21

    The present invention relates to isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  10. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    DOEpatents

    Schnorr, Kirk; Kramer, Randall

    2016-08-09

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  11. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    DOEpatents

    Tang, Lan; Liu, Ye; Duan, Junxin; Zhang, Yu; Jorgensen, Christian Isak; Kramer, Randall

    2013-04-16

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  12. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    DOEpatents

    Duan, Junxin; Tang, Lan; Liu, Ye; Wu, Wenping; Quinlan, Jason; Kramer, Randall

    2013-06-18

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  13. Polypeptides having endoglucanase activity and polynucleotides encoding same

    DOEpatents

    Lopez de Leon, Alfredo; Rey, Michael

    2013-06-18

    The present invention relates to isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  14. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    SciTech Connect

    Morant, Marc D.; Harris, Paul

    2015-10-13

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  15. Polypeptide from a cellulolytic fungus having cellulolytic enhancing activity

    SciTech Connect

    Brown, Kimberly; Harris, Paul; Zaretsky, Elizabeth; Re, Edward; Vlasenko, Elena; McFarland, Keith; Lopez de Leon, Alfredo

    2008-04-22

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  16. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    SciTech Connect

    Lopez de Leon, Alfredo; Ding, Hanshu; Brown, Kimberly

    2012-06-26

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  17. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    SciTech Connect

    Liu, Ye; Tang, Lan; Harris, Paul; Wu, Wenping

    2012-10-02

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  18. Polypeptides having endoglucanase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2016-02-23

    The present invention relates to isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  19. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    DOEpatents

    Stringer, Mary Ann; McBrayer, Brett

    2016-11-29

    The present invention relates to isolated polypeptides having cellobiohydrolase activity, catalytic domains, and cellulose binding domains and polynucleotides encoding the polypeptides, catalytic domains, and cellulose binding domains. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides, catalytic domains, or cellulose binding domains.

  20. Polypeptides having endoglucanase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj; Shagasi, Tarana

    2015-06-30

    The present invention relates to isolated polypeptides having endoglucanase activity, catalytic domains, cellulose binding domains and polynucleotides encoding the polypeptides, catalytic domains or cellulose binding domains. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides, catalytic domains or cellulose binding domains.

  1. Polypeptides having endoglucanase activity and polynucleotides encoding same

    SciTech Connect

    Lopez de Leon, Alfredo; Rey, Michael

    2015-03-10

    The present invention relates to isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  2. Polypeptides having cellulolytic enhancing activity and nucleic acids encoding same

    SciTech Connect

    Brown, Kimberly; Harris, Paul; Zaretsky, Elizabeth; Re, Edward; Vlasenko, Elena; McFarland, Keith; Lopez de Leon, Alfredo

    2012-10-16

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  3. Polypeptides having endoglucanase activity and polynucleotides encoding same

    DOEpatents

    Lopez de Leon, Alfredo; Rey, Michael

    2010-06-22

    The present invention relates to isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  4. Polypeptides having cellulolytic enhancing activity and nucleic acids encoding same

    DOEpatents

    Brown, Kimberly; Harris, Paul; Zaretsky, Elizabeth; Re, Edward; Vlasenko, Elena; McFarland, Keith; Lopez de Leon, Alfredo

    2010-06-22

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  5. Polypeptides having xylanase activity and polynucleotides encoding same

    DOEpatents

    Lopez de Leon, Alfredo; Rey, Michael

    2015-01-27

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  6. Polypeptides having endoglucanase activity and polynucleotides encoding same

    DOEpatents

    Lopez de Leon, Alfredo; Rey, Michael

    2012-09-18

    The present invention relates to isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  7. Polypeptides having xylanase activity and polynucleotides encoding the same

    DOEpatents

    Spodsberg, Nikolaj [Bagsvaed, DK

    2014-01-07

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The inventino also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  8. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding the same

    DOEpatents

    Tang, Lan; Liu, Ye; Duan, Junxin; Zhang, Yu; Jorgensen, Christian Isak; Kramer, Randall

    2013-12-24

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  9. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    DOEpatents

    Maiyuran, Suchindra; Kramer, Randall; Harris, Paul

    2013-10-29

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  10. Polypeptides having xylanase activity and polynucleotides encoding same

    DOEpatents

    Tang, Lan; Liu, Ye; Duan, Junxin; Ding, Hanshu

    2013-04-30

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  11. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding same

    DOEpatents

    Dotson, William D.; Greenier, Jennifer; Ding, Hanshu

    2009-05-19

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated nucleic acids encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the nucleic acids as well as methods for producing and using the polypeptides.

  12. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    DOEpatents

    Harris, Paul; Golightly, Elizabeth

    2007-07-17

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  13. Polypeptides having endoglucanase activity and polynucleotides encoding same

    DOEpatents

    Harris, Paul; Lopez de Leon, Alfredo; Rey, Michael; Ding, Hanshu; Vlasenko, Elena

    2010-11-02

    The present invention relates to isolated polypeptides having endoglucanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  14. Polynucleotides encoding polypeptides having beta-glucosidase activity

    DOEpatents

    Harris, Paul; Golightly, Elizabeth

    2010-03-02

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  15. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    DOEpatents

    Harris, Paul; Golightly, Elizabeth

    2011-06-14

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  16. Polypeptides having xylanase activity and polynucleotides encoding same

    DOEpatents

    Spodsberg, Nikolaj

    2014-10-21

    The present invention relates to isolated polypeptides having xylanase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  17. Polypeptides having cellulolytic enhancing activity and polynucleotides encoding the same

    DOEpatents

    Duan, Junxin; Schnorr, Kirk Matthew; Wu, Wenping

    2013-11-19

    The present invention relates to isolated polypeptides having cellulolytic enhancing activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  18. Polypeptides having cellobiohydrolase activity and polynucleotides encoding same

    DOEpatents

    Brown, Kimberly; Harris, Paul; Lopez De Leon, Alfredo; Merino, Sandra

    2007-05-22

    The present invention relates to isolated polypeptides having cellobiohydrolase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  19. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    SciTech Connect

    Morant, Marc D; Patkar, Shamkant; Ding, Hanshu

    2013-11-12

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  20. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    SciTech Connect

    Morant, Marc Dominique

    2014-10-14

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  1. Polypeptides having beta-glucosidase activity and polynucleotides encoding same

    SciTech Connect

    Harris, Paul; Golightly, Elizabeth

    2012-11-27

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods for producing and using the polypeptides.

  2. Fusion breeder

    SciTech Connect

    Moir, R.W.

    1982-04-20

    The fusion breeder is a fusion reactor designed with special blankets to maximize the transmutation by 14 MeV neutrons of uranium-238 to plutonium or thorium to uranium-233 for use as a fuel for fission reactors. Breeding fissile fuels has not been a goal of the US fusion energy program. This paper suggests it is time for a policy change to make the fusion breeder a goal of the US fusion program and the US nuclear energy program. The purpose of this paper is to suggest this policy change be made and tell why it should be made, and to outline specific research and development goals so that the fusion breeder will be developed in time to meet fissile fuel needs.

  3. Fusion breeder

    SciTech Connect

    Moir, R.W.

    1982-02-22

    The fusion breeder is a fusion reactor designed with special blankets to maximize the transmutation by 14 MeV neutrons of uranium-238 to plutonium or thorium to uranium-233 for use as a fuel for fission reactors. Breeding fissile fuels has not been a goal of the US fusion energy program. This paper suggests it is time for a policy change to make the fusion breeder a goal of the US fusion program and the US nuclear energy program. The purpose of this paper is to suggest this policy change be made and tell why it should be made, and to outline specific research and development goals so that the fusion breeder will be developed in time to meet fissile fuel needs.

  4. POLYPEPTIDE AND POLYSACCHARIDE PROCESSING IN HYPERTHERMOPHILIC MICROORGANISMS

    SciTech Connect

    KELLY, ROBERT M.

    2008-12-22

    This project focused on the microbial physiology and biochemistry of heterotrophic hyperthermophiles with respect to mechanisms by which these organisms process polypeptides and polysaccharides under normal and stressed conditions. Emphasis is on two model organisms, for which completed genome sequences are available: Pyrococcus furiosus (growth Topt of 98°C), an archaeon, and Thermotoga maritima (growth Topt of 80°C), a bacterium. Both organisms are obligately anaerobic heterotrophs that reduce sulfur facultatively. Whole genome cDNA spotted microarrays were used to follow transcriptional response to a variety of environmental conditions in order to identify genes encoding proteins involved in the acquisition, synthesis, processing and utilization of polypeptides and polysaccharides. This project provided new insights into the physiological aspects of hyperthermophiles as these relate to microbial biochemistry and biological function in high temperature habitats. The capacity of these microorganisms to produce biohydrogen from renewable feedstocks makes them important for future efforts to develop biofuels.

  5. Heterogeneity of Glutamine Synthetase Polypeptides in Phaseolus vulgaris L. 1

    PubMed Central

    Lara, Miguel; Porta, Helena; Padilla, Jaime; Folch, Jorge; Sánchez, Federico

    1984-01-01

    Glutamine synthetases from roots, nodules, and leaves of Phaseolus vulgaris L. have been purified to homogeneity and their polypeptide composition determined. The leaf enzyme is composed of six polypeptides. The cytosolic fraction contains two 43,000 dalton polypeptides and the chloroplastic enzyme is formed by four 45,000 dalton polypeptides. Root glutamine synthetase consists only of the same two polypeptides of 43,000 dalton that are present in the leaf enzyme. The nodule enzyme is formed by two polypeptides of 43,000 dalton, one is common to the leaf and root enzyme but the other is specific for N2-fixing nodule tissue. The two glutamine synthetase forms of the nodule contain a different proportion of the 43,000 dalton polypeptides. Images Fig. 1 Fig. 2 Fig. 4 PMID:16663942

  6. Image fusion

    NASA Technical Reports Server (NTRS)

    Pavel, M.

    1993-01-01

    The topics covered include the following: a system overview of the basic components of a system designed to improve the ability of a pilot to fly through low-visibility conditions such as fog; the role of visual sciences; fusion issues; sensor characterization; sources of information; image processing; and image fusion.

  7. Influence of Elastin-Like Polypeptide and Hydrophobin on Recombinant Hemagglutinin Accumulations in Transgenic Tobacco Plants

    PubMed Central

    Phan, Hoang Trong; Hause, Bettina; Hause, Gerd; Arcalis, Elsa; Stoger, Eva; Maresch, Daniel; Altmann, Friedrich; Joensuu, Jussi; Conrad, Udo

    2014-01-01

    Fusion protein strategies are useful tools to enhance expression and to support the development of purification technologies. The capacity of fusion protein strategies to enhance expression was explored in tobacco leaves and seeds. C-terminal fusion of elastin-like polypeptides (ELP) to influenza hemagglutinin under the control of either the constitutive CaMV 35S or the seed-specific USP promoter resulted in increased accumulation in both leaves and seeds compared to the unfused hemagglutinin. The addition of a hydrophobin to the C-terminal end of hemagglutinin did not significantly increase the expression level. We show here that, depending on the target protein, both hydrophobin fusion and ELPylation combined with endoplasmic reticulum (ER) targeting induced protein bodies in leaves as well as in seeds. The N-glycosylation pattern indicated that KDEL sequence-mediated retention of leaf-derived hemagglutinins and hemagglutinin-hydrophobin fusions were not completely retained in the ER. In contrast, hemagglutinin-ELP from leaves contained only the oligomannose form, suggesting complete ER retention. In seeds, ER retention seems to be nearly complete for all three constructs. An easy and scalable purification method for ELPylated proteins using membrane-based inverse transition cycling could be applied to both leaf- and seed-expressed hemagglutinins. PMID:24914995

  8. Fusion Power.

    ERIC Educational Resources Information Center

    Dingee, David A.

    1979-01-01

    Discusses the extraordinary potential, the technical difficulties, and the financial problems that are associated with research and development of fusion power plants as a major source of energy. (GA)

  9. ANTIGENICITY OF POLYPEPTIDES (POLY ALPHA AMINO ACIDS)

    PubMed Central

    Pinchuck, Paul; Maurer, Paul H.

    1965-01-01

    The response of mice to synthetic linear polypeptides of known composition but random sequence has been studied. Neither Swiss mice nor a number of inbred strains could respond to copolymers of only 2 amino acids (G60L40, G60A40, G90T10). Upon introduction of as little as 4 mole per cent of a third amino acid, good immune responses were obtained, regardless of the nature of the third amino acid. The level of the immune response to a series of glu-lys-ala polymers increased with increasing alanine content of the polymer. PMID:5849232

  10. Pulsed ELDOR in spin-labeled polypeptides

    NASA Astrophysics Data System (ADS)

    Milov, Alexander D.; Maryasov, Alexander G.; Tsvetkov, Yuri D.; Raap, Jan

    1999-04-01

    The pulsed electron-electron double-resonance (PELDOR) technique was applied to obtain information about the structure of the synthetic polypeptide-biradical in a frozen glassy solution. From the concentration dependence of the PELDOR signal, the effects of intermolecular and intramolecular interactions were separated. It was found that the intramolecular dipole-dipole interactions in the biradical peptide led to the modulation effects in the PELDOR signal decay. This may be attributed to the existence of a conformational population having a distance between the two unpaired electrons of ˜20 Å with a distribution of (˜2 Å). Its fraction is estimated as about 25%.

  11. Ordered Nanostructures Made Using Chaperonin Polypeptides

    NASA Technical Reports Server (NTRS)

    Trent, Jonathan; McMillan, Robert; Paavola, Chad; Mogul, Rakesh; Kagawa, Hiromi

    2004-01-01

    A recently invented method of fabricating periodic or otherwise ordered nanostructures involves the use of chaperonin polypeptides. The method is intended to serve as a potentially superior and less expensive alternative to conventional lithographic methods for use in the patterning steps of the fabrication of diverse objects characterized by features of the order of nanometers. Typical examples of such objects include arrays of quantum dots that would serve as the functional building blocks of future advanced electronic and photonic devices. A chaperonin is a double-ring protein structure having a molecular weight of about 60 plus or minus 5 kilodaltons. In nature, chaperonins are ubiquitous, essential, subcellular structures. Each natural chaperonin molecule comprises 14, 16, or 18 protein subunits, arranged as two stacked rings approximately 16 to 18 nm tall by approximately 15 to 17 nm wide, the exact dimensions depending on the biological species in which it originates. The natural role of chaperonins is unknown, but they are believed to aid in the correct folding of other proteins, by enclosing unfolded proteins and preventing nonspecific aggregation during assembly. What makes chaperonins useful for the purpose of the present method is that under the proper conditions, chaperonin rings assemble themselves into higher-order structures. This method exploits such higher-order structures to define nanoscale devices. The higher-order structures are tailored partly by choice of chemical and physical conditions for assembly and partly by using chaperonins that have been mutated. The mutations are made by established biochemical techniques. The assembly of chaperonin polypeptides into such structures as rings, tubes, filaments, and sheets (two-dimensional crystals) can be regulated chemically. Rings, tubes, and filaments of some chaperonin polypeptides can, for example, function as nano vessels if they are able to absorb, retain, protect, and release gases or

  12. Polypeptide having acetyl xylan esterase activity and uses thereof

    SciTech Connect

    Schoonneveld-Bergmans, Margot Elisabeth Francoise; Heijne, Wilbert Herman Marie; Los, Alrik Pieter

    2015-10-20

    The invention relates to a polypeptide comprising the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 82% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 82% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional polypeptide and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  13. Polypeptide having carbohydrate degrading activity and uses thereof

    SciTech Connect

    Schooneveld-Bergmans, Margot Elisabeth Francoise; Heijne, Wilbert Herman Marie; Vlasie, Monica Diana; Damveld, Robbertus Antonius

    2015-08-18

    The invention relates to a polypeptide comprising the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 73% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 73% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional polypeptide and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  14. Polypeptide having beta-glucosidase activity and uses thereof

    SciTech Connect

    Schooneveld-Bergmans, Margot Elisabeth Francoise; Heijne, Wilbert Herman Marie; De Jong, Rene Marcel; Damveld, Robbertus Antonius

    2015-09-01

    The invention relates to a polypeptide comprising the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 70% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 70% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional polypeptide and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  15. Polypeptide having beta-glucosidase activity and uses thereof

    SciTech Connect

    Schoonneveld-Bergmans, Margot Elisabeth Francoise; Heijne, Wilbert Herman Marie; De Jong, Rene Marcel; Damveld, Robbertus Antonius

    2016-09-13

    The invention relates to a polypeptide comprising the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 96% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 96% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional polypeptide and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  16. Expression and purification of short hydrophobic elastin-like polypeptides with maltose-binding protein as a solubility tag.

    PubMed

    Bataille, Laure; Dieryck, Wilfrid; Hocquellet, Agnès; Cabanne, Charlotte; Bathany, Katell; Lecommandoux, Sébastien; Garbay, Bertrand; Garanger, Elisabeth

    2015-06-01

    Elastin-like polypeptides (ELPs) are biodegradable polymers with interesting physico-chemical properties for biomedical and biotechnological applications. The recombinant expression of hydrophobic elastin-like polypeptides is often difficult because they possess low transition temperatures, and therefore form aggregates at sub-ambient temperatures. To circumvent this difficulty, we expressed in Escherichia coli three hydrophobic ELPs (VPGIG)n with variable lengths (n=20, 40, and 60) in fusion with the maltose-binding protein (MBP). Fusion proteins were soluble and yields of purified MBP-ELP ranged between 66 and 127mg/L culture. After digestion of the fusion proteins by enterokinase, the ELP moiety was purified by using inverse transition cycling. The purified fraction containing ELP40 was slightly contaminated by traces of undigested fusion protein. Purification of ELP60 was impaired because of co-purification of the MBP tag during inverse transition cycling. ELP20 was successfully purified to homogeneity, as assessed by gel electrophoresis and mass spectrometry analyses. The transition temperature of ELP20 was measured at 15.4°C in low salt buffer. In conclusion, this method can be used to produce hydrophobic ELP of low molecular mass.

  17. Facilitated Translocation of Polypeptides Through A Single Nanopore

    PubMed Central

    Bikwemu, Robert; Wolfe, Aaron J.; Xing, Xiangjun; Movileanu, Liviu

    2011-01-01

    The transport of polypeptides through nanopores is a key process in biology and medical biotechnology. Despite its critical importance, the underlying kinetics of polypeptide translocation through protein nanopores is not yet comprehensively understood. Here, we present a simple two-barrier, one-well kinetic model for the translocation of short positively charged polypeptides through a single transmembrane protein nanopore that is equiped with negatively charged rings, simply called traps. We demonstrate that the presence of these traps within the interior of the nanopore dramatically alters the free energy landscape for the partitioning of the polypeptide into the nanopore interior, as revealed by significant modifications in the activation free energies required for the transitions of the polypeptide from one state to other. Our kinetic model permits the calculation of the relative and absolute exit frequencies of the short cationic polypeptides through either opening of the nanopore. Moreover, this approach enabled quantitative assessment of the kinetics of translocation of the polypeptides through a protein nanopore, which is strongly dependent on several factors, including the nature of the translocating polypeptide, the position of the traps, the strength of the polypeptide-attractive trap interactions and the applied transmembrane voltage. PMID:21339604

  18. Intracellularly Swollen Polypeptide Nanogel Assists Hepatoma Chemotherapy

    PubMed Central

    Shi, Bo; Huang, Kexin; Ding, Jianxun; Xu, Weiguo; Yang, Yu; Liu, Haiyan; Yan, Lesan; Chen, Xuesi

    2017-01-01

    Nowadays, chemotherapy is one of the principal modes of treatment for tumor patients. However, the traditional formulations of small molecule drugs show short circulation time, low tumor selectivity, and high toxicity to normal tissues. To address these problems, a facilely prepared, and pH and reduction dual-responsive polypeptide nanogel was prepared for selectively intracellular delivery of chemotherapy drug. As a model drug, doxorubicin (DOX) was loaded into the nanogel through a sequential dispersion and dialysis technique, resulting in a high drug loading efficiency (DLE) of 96.7 wt.%. The loading nanogel, defined as NG/DOX, exhibited a uniform spherical morphology with a mean hydrodynamic radius of 58.8 nm, pH and reduction dual-triggered DOX release, efficient cell uptake, and cell proliferation inhibition in vitro. Moreover, NG/DOX exhibited improved antitumor efficacy toward H22 hepatoma-bearing BALB/c mouse model compared with free DOX·HCl. Histopathological and immunohistochemical analyses were implemented to further confirm the tumor suppression activity of NG/DOX. Furthermore, the variations of body weight, histopathological morphology, bone marrow cell micronucleus rate, and white blood cell count verified that NG/DOX showed excellent safety in vivo. With these excellent properties in vitro and in vivo, the pH and reduction dual-responsive polypeptide nanogel exhibits great potential for on-demand intracellular delivery of antitumor drug, and holds good prospect for future clinical application. PMID:28255361

  19. Simplified lattice model for polypeptide fibrillar transitions

    NASA Astrophysics Data System (ADS)

    Xiao, Xuhui; Wu, Ming-Chya

    2014-10-01

    Polypeptide fibrillar transitions are studied using a simplified lattice model, modified from the three-state Potts model, where uniform residues as spins, placed on a cubic lattice, can interact with neighbors to form coil, helical, sheet, or fibrillar structure. Using the transfer matrix method and numerical calculations, we analyzed the partition function and construct phase diagrams. The model manifests phase transitions among coil, helix, sheet, and fibril through parameterizing bond coupling energy ɛh,ɛs,ɛf, structural entropies sh,ss,sf of helical, sheet, and fibrillar states, and number density ρ. The phase diagrams show the transition sequence is basically governed by ɛh, ɛs, and ɛf, while the transition temperature is determined by the competition among ɛh, ɛs, and ɛf, as well as sh, ss, sf, and ρ. Furthermore, the fibrillation is accompanied with an abrupt phase transition from coil, helix, or sheet to fibril even for short polypeptide length, resembling the feature of nucleation-growth process. The finite-size effect in specific heat at transitions for the nonfibrillation case can be described by the scaling form of lattice model. With rich phase-transition properties, our model provides a useful reference for protein aggregation experiments and modeling.

  20. Laser fusion

    SciTech Connect

    Smit, W.A.; Boskma, P.

    1980-12-01

    Unrestricted laser fusion offers nations an opportunity to circumvent arms control agreements and develop thermonuclear weapons. Early laser weapons research sought a clean radiation-free bomb to replace the fission bomb, but this was deceptive because a fission bomb was needed to trigger the fusion reaction and additional radioactivity was induced by generating fast neutrons. As laser-implosion experiments focused on weapons physics, simulating weapons effects, and applications for new weapons, the military interest shifted from developing a laser-ignited hydrogen bomb to more sophisticated weapons and civilian applications for power generation. Civilian and military research now overlap, making it possible for several countries to continue weapons activities and permitting proliferation of nuclear weapons. These countries are reluctant to include inertial confinement fusion research in the Non-Proliferation Treaty. 16 references. (DCK)

  1. Chain stiffness of elastin-like polypeptides

    PubMed Central

    Fluegel, Sabine; Fischer, Karl; McDaniel, Jonathan R.; Chilkoti, Ashutosh; Schmidt, Manfred

    2010-01-01

    The hydrodynamic radii of a series of genetically engineered monodisperse elastin like polypeptides (ELP) was determined by dynamic light scattering in aqueous solution as function of molar mass. Utilizing the known theoretical expression for the hydrodynamic radius of wormlike chains, the Kuhn statistical segment length was determined to be lk = 2.1 nm, assuming that the length of the peptide repeat unit was b = 0.365 nm, a value derived for a coiled conformation of ELP. The resulting chain stiffness is significantly larger than previously reported by force-distance curve analysis (lk < 0.4 nm). The possible occurrence of superstructures, such as hairpins or helices, would reduce the contour length of the ELP, further increasing lk. Accordingly, the value lk = 2.1 nm reported here represents a lower limit of the chain stiffness for ELP. PMID:20961120

  2. Fibrillar dimer formation of islet amyloid polypeptides

    NASA Astrophysics Data System (ADS)

    Chiu, Chi-cheng; de Pablo, Juan J.

    2015-09-01

    Amyloid deposits of human islet amyloid polypeptide (hIAPP), a 37-residue hormone co-produced with insulin, have been implicated in the development of type 2 diabetes. Residues 20 - 29 of hIAPP have been proposed to constitute the amyloidogenic core for the aggregation process, yet the segment is mostly unstructured in the mature fibril, according to solid-state NMR data. Here we use molecular simulations combined with bias-exchange metadynamics to characterize the conformational free energies of hIAPP fibrillar dimer and its derivative, pramlintide. We show that residues 20 - 29 are involved in an intermediate that exhibits transient β-sheets, consistent with recent experimental and simulation results. By comparing the aggregation of hIAPP and pramlintide, we illustrate the effects of proline residues on inhibition of the dimerization of IAPP. The mechanistic insights presented here could be useful for development of therapeutic inhibitors of hIAPP amyloid formation.

  3. Fibrillar dimer formation of islet amyloid polypeptides

    SciTech Connect

    Chiu, Chi -cheng; de Pablo, Juan J.

    2015-05-08

    Amyloid deposits of human islet amyloid polypeptide (hIAPP), a 37-residue hormone co-produced with insulin, have been implicated in the development of type 2 diabetes. Residues 20 – 29 of hIAPP have been proposed to constitute the amyloidogenic core for the aggregation process, yet the segment is mostly unstructured in the mature fibril, according to solid-state NMR data. Here we use molecular simulations combined with bias-exchange metadynamics to characterize the conformational free energies of hIAPP fibrillar dimer and its derivative, pramlintide. We show that residues 20 – 29 are involved in an intermediate that exhibits transient β-sheets, consistent with recent experimental and simulation results. By comparing the aggregation of hIAPP and pramlintide, we illustrate the effects of proline residues on inhibition of the dimerization of IAPP. The mechanistic insights presented here could be useful for development of therapeutic inhibitors of hIAPP amyloid formation.

  4. Chirality-selected phase behaviour in ionic polypeptide complexes

    DOE PAGES

    Perry, Sarah L.; Leon, Lorraine; Hoffmann, Kyle Q.; ...

    2015-01-14

    In this study, polyelectrolyte complexes present new opportunities for self-assembled soft matter. Factors determining whether the phase of the complex is solid or liquid remain unclear. Ionic polypeptides enable examination of the effects of stereochemistry on complex formation. Here we demonstrate that chirality determines the state of polyelectrolyte complexes, formed from mixing dilute solutions of oppositely charged polypeptides, via a combination of electrostatic and hydrogen-bonding interactions. Fluid complexes occur when at least one of the polypeptides in the mixture is racemic, which disrupts backbone hydrogen-bonding networks. Pairs of purely chiral polypeptides, of any sense, form compact, fibrillar solids with amore » β-sheet structure. Analogous behaviour occurs in micelles formed from polypeptide block copolymers with polyethylene oxide, where assembly into aggregates with either solid or fluid cores, and eventually into ordered phases at high concentrations, is possible. Chirality is an exploitable tool for manipulating material properties in polyelectrolyte complexation.« less

  5. Nucleic acids encoding antifungal polypeptides and uses thereof

    DOEpatents

    Altier, Daniel J.; Ellanskaya, I. A.; Gilliam, Jacob T.; Hunter-Cevera, Jennie; Presnail, James K; Schepers, Eric; Simmons, Carl R.; Torok, Tamas; Yalpani, Nasser

    2010-11-02

    Compositions and methods for protecting a plant from a pathogen, particularly a fungal pathogen, are provided. Compositions include an amino acid sequence, and variants and fragments thereof, for an antipathogenic polypeptide that was isolated from a fungal fermentation broth. Nucleic acid molecules that encode the antipathogenic polypeptides of the invention, and antipathogenic domains thereof, are also provided. A method for inducing pathogen resistance in a plant using the nucleotide sequences disclosed herein is further provided. The method comprises introducing into a plant an expression cassette comprising a promoter operably linked to a nucleotide sequence that encodes an antipathogenic polypeptide of the invention. Compositions comprising an antipathogenic polypeptide or a transformed microorganism comprising a nucleic acid of the invention in combination with a carrier and methods of using these compositions to protect a plant from a pathogen are further provided. Transformed plants, plant cells, seeds, and microorganisms comprising a nucleotide sequence that encodes an antipathogenic polypeptide of the invention are also disclosed.

  6. Chirality-selected phase behaviour in ionic polypeptide complexes

    SciTech Connect

    Perry, Sarah L.; Leon, Lorraine; Hoffmann, Kyle Q.; Kade, Matthew J.; Priftis, Dimitrios; Black, Katie A.; Wong, Derek; Klein, Ryan A.; Pierce, III, Charles F.; Margossian, Khatcher O.; Whitmer, Jonathan K.; Qin, Jian; de Pablo, Juan J.; Tirrell, Matthew

    2015-01-14

    In this study, polyelectrolyte complexes present new opportunities for self-assembled soft matter. Factors determining whether the phase of the complex is solid or liquid remain unclear. Ionic polypeptides enable examination of the effects of stereochemistry on complex formation. Here we demonstrate that chirality determines the state of polyelectrolyte complexes, formed from mixing dilute solutions of oppositely charged polypeptides, via a combination of electrostatic and hydrogen-bonding interactions. Fluid complexes occur when at least one of the polypeptides in the mixture is racemic, which disrupts backbone hydrogen-bonding networks. Pairs of purely chiral polypeptides, of any sense, form compact, fibrillar solids with a β-sheet structure. Analogous behaviour occurs in micelles formed from polypeptide block copolymers with polyethylene oxide, where assembly into aggregates with either solid or fluid cores, and eventually into ordered phases at high concentrations, is possible. Chirality is an exploitable tool for manipulating material properties in polyelectrolyte complexation.

  7. Chirality-selected phase behaviour in ionic polypeptide complexes

    NASA Astrophysics Data System (ADS)

    Perry, Sarah L.; Leon, Lorraine; Hoffmann, Kyle Q.; Kade, Matthew J.; Priftis, Dimitrios; Black, Katie A.; Wong, Derek; Klein, Ryan A.; Pierce, Charles F.; Margossian, Khatcher O.; Whitmer, Jonathan K.; Qin, Jian; de Pablo, Juan J.; Tirrell, Matthew

    2015-01-01

    Polyelectrolyte complexes present new opportunities for self-assembled soft matter. Factors determining whether the phase of the complex is solid or liquid remain unclear. Ionic polypeptides enable examination of the effects of stereochemistry on complex formation. Here we demonstrate that chirality determines the state of polyelectrolyte complexes, formed from mixing dilute solutions of oppositely charged polypeptides, via a combination of electrostatic and hydrogen-bonding interactions. Fluid complexes occur when at least one of the polypeptides in the mixture is racemic, which disrupts backbone hydrogen-bonding networks. Pairs of purely chiral polypeptides, of any sense, form compact, fibrillar solids with a β-sheet structure. Analogous behaviour occurs in micelles formed from polypeptide block copolymers with polyethylene oxide, where assembly into aggregates with either solid or fluid cores, and eventually into ordered phases at high concentrations, is possible. Chirality is an exploitable tool for manipulating material properties in polyelectrolyte complexation.

  8. Chirality-selected phase behaviour in ionic polypeptide complexes

    PubMed Central

    Perry, Sarah L.; Leon, Lorraine; Hoffmann, Kyle Q.; Kade, Matthew J.; Priftis, Dimitrios; Black, Katie A.; Wong, Derek; Klein, Ryan A.; Pierce, Charles F.; Margossian, Khatcher O.; Whitmer, Jonathan K.; Qin, Jian; de Pablo, Juan J.; Tirrell, Matthew

    2015-01-01

    Polyelectrolyte complexes present new opportunities for self-assembled soft matter. Factors determining whether the phase of the complex is solid or liquid remain unclear. Ionic polypeptides enable examination of the effects of stereochemistry on complex formation. Here we demonstrate that chirality determines the state of polyelectrolyte complexes, formed from mixing dilute solutions of oppositely charged polypeptides, via a combination of electrostatic and hydrogen-bonding interactions. Fluid complexes occur when at least one of the polypeptides in the mixture is racemic, which disrupts backbone hydrogen-bonding networks. Pairs of purely chiral polypeptides, of any sense, form compact, fibrillar solids with a β-sheet structure. Analogous behaviour occurs in micelles formed from polypeptide block copolymers with polyethylene oxide, where assembly into aggregates with either solid or fluid cores, and eventually into ordered phases at high concentrations, is possible. Chirality is an exploitable tool for manipulating material properties in polyelectrolyte complexation. PMID:25586861

  9. Isolated nucleic acids encoding antipathogenic polypeptides and uses thereof

    DOEpatents

    Altier, Daniel J.; Crane, Virginia C.; Ellanskaya, Irina; Ellanskaya, Natalia; Gilliam, Jacob T.; Hunter-Cevera, Jennie; Presnail, James K.; Schepers, Eric J.; Simmons, Carl R.; Torok, Tamas; Yalpani, Nasser

    2010-04-20

    Compositions and methods for protecting a plant from a pathogen, particularly a fungal pathogen, are provided. Compositions include amino acid sequences, and variants and fragments thereof, for antipathogenic polypeptides that were isolated from fungal fermentation broths. Nucleic acids that encode the antipathogenic polypeptides are also provided. A method for inducing pathogen resistance in a plant using the nucleotide sequences disclosed herein is further provided. The method comprises introducing into a plant an expression cassette comprising a promoter operably linked to a nucleotide sequence that encodes an antipathogenic polypeptide of the invention. Compositions comprising an antipathogenic polypeptide or a transformed microorganism comprising a nucleic acid of the invention in combination with a carrier and methods of using these compositions to protect a plant from a pathogen are further provided. Transformed plants, plant cells, seeds, and microorganisms comprising a nucleotide sequence that encodes an antipathogenic polypeptide of the invention are also disclosed.

  10. Spinal fusion

    MedlinePlus

    Liu G, Wong HK. Laminectomy and fusion. In: Shen FH, Samartzis D, Fessler RG, eds. Textbook of the Cervical Spine . Philadelphia, PA: Elsevier Saunders; 2015:chap 34. Wood GW. Arthrodesis of the spine. In: Canale ST, Beaty JH, eds. Campbell's Operative ...

  11. Clinical endocrinology and metabolism. Glucose-dependent insulinotropic polypeptide/gastric inhibitory polypeptide.

    PubMed

    Meier, Juris J; Nauck, Michael A

    2004-12-01

    The 42 amino acid polypeptide glucose-dependent insulinotropic polypeptide/gastric inhibitory polypeptide (GIP) is released from intestinal K-cells in response to nutrient ingestion. Based on animal studies, the peptide was initially assumed to act as an endogenous inhibitor of gastric acid secretion. Later it was found that GIP is capable of augmenting glucose-stimulated insulin secretion, and subsequent studies provided evidence that, in humans, the peptide predominantly acts as an incretin hormone. A role for GIP in the regulation of lipid homeostasis and in the development of obesity has been inferred from different animal studies. While GIP strongly stimulates insulin release in healthy humans, the peptide has almost completely lost its insulinotropic effect in patients with type 2 diabetes. This is different from the actions of glucagon-like peptide 1, which stimulates insulin secretion even in the later stages of type 2 diabetes. This suggests that a diminished insulinotropic effect of GIP may contribute to the pathogenesis of type 2 diabetes. This review will summarize the actions of GIP in human physiology and discuss its role in the pathogenesis of type 2 diabetes, as well as the therapeutic options derived from these findings.

  12. Cold fusion, Alchemist's dream

    SciTech Connect

    Clayton, E.D.

    1989-09-01

    In this report the following topics relating to cold fusion are discussed: muon catalysed cold fusion; piezonuclear fusion; sundry explanations pertaining to cold fusion; cosmic ray muon catalysed cold fusion; vibrational mechanisms in excited states of D{sub 2} molecules; barrier penetration probabilities within the hydrogenated metal lattice/piezonuclear fusion; branching ratios of D{sub 2} fusion at low energies; fusion of deuterons into {sup 4}He; secondary D+T fusion within the hydrogenated metal lattice; {sup 3}He to {sup 4}He ratio within the metal lattice; shock induced fusion; and anomalously high isotopic ratios of {sup 3}He/{sup 4}He.

  13. Laser enhanced hydrolysis of selected polypeptides

    NASA Astrophysics Data System (ADS)

    Ouzts, Mary Paige

    This project serves as a preliminary examination of selectively enhancing bond cleavage during chemical reactions in biological molecules by using continuous wave infrared lasers. To analyze protein content, polypeptides are broken into their constituent amino acids through hydrolysis. The cleaving of the peptide bond has traditionally been accomplished under harsh conditions, 110°C in 6 N hydrochloric acid for 24 hours. In this project hydrolysis was strongly enhanced by irradiating the dipeptides, threonyl-aspartate and alanyl-alanine, for 30 minutes with coherent infrared radiation from a tunable carbon dioxide laser. The dipeptide tyrosyl-tyrosine, the chemical N- methylacetimide, and the protein BSA were successfully hydrolyzed with the laser. The effect of reaction parameters such as laser power and HCl concentration were studied, as well as the effect of the primary parameter, the beam wavelength. The samples were analyzed using standard biological methods for determining the amino acid concentration, thin layer chromatography and ion exchange chromatography. These methods gave consistent results for the irradiated samples as well as for standard amino acids and polypeptide samples. The results from these methods were used to create the hydrolysis spectra. The catalytic action of the laser was strongly wavelength dependent. The hydrolysis spectra of the molecules were compared to the absorption spectra of the samples. Laser enhanced hydrolysis occurred when the laser wavelength coincided with a line in the dipeptide spectra. This weak line in each of the dipeptide spectra is consistent both in position and strength with a line in NMA, which has been identified as a fundamental mode associated with the peptide bond. From the experimental results, the enhanced process appears to occur in the vapor phase. The initially liquid sample was progressively evaporated, and fully hydrolyzed material was carried to a collection trap by the vapor. It can, in principle

  14. Simulating Massive Conformation Changes within Polypeptide Systems

    NASA Astrophysics Data System (ADS)

    Singh, Jaspinder Paul

    In this dissertation I employ all-atom structure based models with stable energy basins to several existing and novel polypeptide systems (postulated conformation changes of the mammalian prion protein and structurally dual proteins). The common themes are finding unfolding and refolding pathways between highly dissimilar protein structures as a means of understanding exactly how and why a protein may misfold. The modeling is based on the energy funnel landscape theory of protein conformation space. The principle of minimal frustration is considered as the model includes parameters which vary the roughness of the landscape and give rise to off-pathway misfoldings. The dual basin model is applied to the C-terminal (residues 166-226) of the mammalian prion protein. One basin represents the known alpha-helical (aH) structure while the other represents the same residues in a lefthanded beta-helical (LHBH) conformation. The LHBH structure has been proposed to help describe one class of in vitro grown fibrils, as well as possibly self-templating the conversion of normal cellular prion protein to the infectious form. Yet, it is unclear how the protein may make this global rearrangement. Our results demonstrate that the conformation changes are not strongly limited by large-scale geometry modification and that there may exist an overall preference for the LHBH conformation. Furthermore, our model presents novel intermediate trapping conformations with twisted LHBH structure. Polypeptides that display structural duality have primary structures that can give rise to different potential native conformations. We apply the structure-based all-atom model to a leucine zipper protein template with a stable aH structure that has been shown in experiment to switch to a β hairpin structure when exposed to a low-pH environment. We show that the model can be used to perform large-scale temperature-dependent conformational switching by simulating this switching behavior. We augmented

  15. Elastin-like Polypeptide Based Hydroxyapatite Bionanocomposites

    PubMed Central

    Wang, Eddie; Lee, Sang-Hyuk; Lee, Seung-Wuk

    2011-01-01

    In nature, organic matrix macromolecules play a critical role in enhancing the mechanical properties of biomineralized composites such as bone and teeth. Designing artificial matrix analogues is promising but challenging because relatively little is known about how natural matrix components function. Therefore, in lieu of using natural components, we created biomimetic matrices using genetically engineered elastin-like polypeptides (ELPs) then used them to construct mechanically robust ELP-hydroxyapatite (HAP) composites. ELPs were engineered with well-defined backbone charge distributions by periodic incorporation of negative, positive, or neutral side chains or with HAP-binding octaglutamic acid motifs at one or both protein termini. ELPs exhibited sequence-specific capacities to interact with ions, bind HAP, and disperse HAP nanoparticles. HAP-binding ELPs were incorporated into calcium phosphate cements resulting in materials with improved mechanical strength, injectability, and anti-washout properties. The results demonstrate that rational design of genetically engineered polymers is a powerful system for determining sequence-property relationships and for improving the properties of organic-inorganic composites. Our approach may be used to further develop novel, multifunctional bone cements and expanded to the design of other advanced composites. PMID:21218767

  16. Fibrillar dimer formation of islet amyloid polypeptides

    DOE PAGES

    Chiu, Chi -cheng; de Pablo, Juan J.

    2015-05-08

    Amyloid deposits of human islet amyloid polypeptide (hIAPP), a 37-residue hormone co-produced with insulin, have been implicated in the development of type 2 diabetes. Residues 20 – 29 of hIAPP have been proposed to constitute the amyloidogenic core for the aggregation process, yet the segment is mostly unstructured in the mature fibril, according to solid-state NMR data. Here we use molecular simulations combined with bias-exchange metadynamics to characterize the conformational free energies of hIAPP fibrillar dimer and its derivative, pramlintide. We show that residues 20 – 29 are involved in an intermediate that exhibits transient β-sheets, consistent with recent experimentalmore » and simulation results. By comparing the aggregation of hIAPP and pramlintide, we illustrate the effects of proline residues on inhibition of the dimerization of IAPP. The mechanistic insights presented here could be useful for development of therapeutic inhibitors of hIAPP amyloid formation.« less

  17. Mechanisms of stability of electrospun polypeptide fibers

    NASA Astrophysics Data System (ADS)

    Gitnik, Alina; Khadka, Dhan; Cross, Michael; Le, Nicole; Haynie, Donald

    2013-03-01

    Electrospun nano- and microfibers made of biodegradable and absorbable polymers are of great interest in biomedical engineering for tissue engineering, wound healing and other purposes. We have investigated physical properties of fibers made of the synthetic organic polymer co-poly(L-glutamic acid4, L-tyrosine1) (PLEY). This water-soluble polypeptide has a net negative charge at neutral pH. Dehydrated fibers are crosslinked with a diimide reagent dissolved in ethanol, giving a maximum average number of crosslinks of 1 per polymer molecule. Fiber integrity has been assessed in an aqueous medium at pH 2, 7 and 12, before and after crosslinking. Non-crosslinked fibers dissolved rapidly at all pH values, on a timescale of seconds to minutes. Crosslinked fibers dissolved completely at pH 12, but not at pH 2 or pH 7, the rate depending on the concentration of crosslinking reagent and therefore the density of crosslinks. Dissolution at pH 12 is attributable to ionization of the tyrosine side chain, which has a nominal pKa of 10.4, an increase in electrostatic repulsion between side chains and the migration of counterions into the fiber. Fibers crosslinked in 50 mM EDC buckled on a timescale of minutes at pH 12 and dissolved shortly thereafter. Funding provided by the National Science Foundation

  18. cDNA encoding a polypeptide including a hev ein sequence

    DOEpatents

    Raikhel, Natasha V.; Broekaert, Willem F.; Chua, Nam-Hai; Kush, Anil

    2000-07-04

    A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

  19. Polypeptide and RNA composition of the reticuloendotheliosis viruses.

    PubMed

    Maldonado, R L; Bose, H R

    1975-01-01

    The RNA and polypeptide composition of chick syncytial virus (CSV) and duck infectious anemia virus (DIAV) was investigated and compared to that of reticuloendotheliosis virus (REV) strain T, the prototype of the newly recognized REV group of viruses. CSV and DIAV contain genomic RNA species which cosediment with those of REV in sucrose gradients. Five or six polypeptides, two of which are glycoproteins, were consistently found in CSV and DIAV preparations. The major nonglycosylated polypeptides and glycoproteins of CSV and DIAV comigrated with the corresponding polypeptides of REV strain T. Since the genomic RNA species and the glycoproteins of avian tumor viruses fail to comigrate, this suggests that the REV complex is a more homogeneous group.

  20. Controlling assembly of helical polypeptides via PEGylation strategies†

    PubMed Central

    Top, Ayben; Zhong, Sheng; Yan, Congqi

    2013-01-01

    Recent studies in our laboratories have demonstrated that a helical polypeptide (17H6), equipped with a histidine tag and a helical alanine-rich, glutamic-acid-containing domain, exhibits pH-responsive assembly behavior useful in the production of polymorphological nanostructures. In this study, the histidine tag in these polypeptides was replaced by polyethylene glycol (PEG) with different molecular masses (5 kDa, or 10 kDa), and the self-association behavior of 17H6 and the PEGylated conjugates was characterized via dynamic light scattering (DLS), small angle neutron scattering (SANS), and cryogenic transmission electron microscopy (cryo-TEM). DLS experiments illustrated that the polypeptide and its PEG-conjugates undergo reversible assembly under acidic conditions, suggesting that the aggregation state of the polypeptide and the conjugates is controlled by the charged state of the glutamic acid residues. Nanoscale aggregates were detected at polypeptide/conjugate concentrations as low as 20 μM (∼0.3–0.5 mg ml−1) at physiological and ambient temperatures. Scattering and microscopy results showed that the size, the aggregation number, and the morphology of the aggregates can be tuned by the size and the nature of the hydrophilic tag. This tunable nature of the morphology of the aggregates, along with their low critical aggregation concentration, suggests that PEG-alanine-rich polypeptide conjugates may be useful as drug delivery vehicles in which the alanine-rich block serves as a drug attachment domain. PMID:24039625

  1. Aqueous cholesteric liquid crystals using uncharged rodlike polypeptides. Polypeptide vesicles by conformation-specific assembly. Ordered chiral macroporous hybrid silica-polypeptide composites

    NASA Astrophysics Data System (ADS)

    Bellomo, Enrico Giuseppe

    2005-07-01

    Aqueous cholesteric liquid crystals using uncharged rodlike polypeptides . The aqueous, lyotropic liquid-crystalline phase behavior of an alpha helical polypeptide, has been studied using optical microscopy and X-ray scattering. Solutions of optically pure polypeptide were found to form cholesteric liquid crystals at volume fractions that decreased with increasing average chain length. At very high volume fractions, the formation of a hexagonal mesophase was observed. The pitch of the cholesteric phase could be varied by a mixture of enantiomeric samples, where the pitch increased as the mixture approached equimolar. The cholesteric phases could be untwisted, using either magnetic field or shear flow, into nematic phases, which relaxed into cholesterics upon removal of field or shear. We have found that the phase diagram of this polypeptide in aqueous solution parallels that of poly(gamma-benzyl glutamate) in organic solvents, thus providing a useful system for liquid-crystal applications requiring water as solvent. Polypeptide vesicles by conformation-specific assembly. We have found that block copolymers composed of polypeptide segments provide significant advantages in controlling both the function and supramolecular structure of bioinspired self-assemblies. Incorporation of the stable chain conformations found in proteins into block copolymers was found to provide an additional element of control, beyond amphiphilicity and composition that defines self-assembled architecture. The abundance of functionality present in amino acids, and the ease by which they can be incorporated into these materials, also provides a powerful mechanism to impart block copolypeptides with function. This combination of structure and function work synergistically to enable significant advantages in the preparation of therapeutic agents as well as provide insight into design of self-assemblies beginning to approach the complexity of natural structures such as virus capsids. Ordered

  2. Design and cellular internalization of genetically engineered polypeptide nanoparticles displaying adenovirus knob domain

    PubMed Central

    Sun, Guoyong; Hsueh, Pang-Yu; Janib, Siti M.; Hamm-Alvarez, Sarah; MacKay, J. Andrew

    2011-01-01

    Hepatocytes and acinar cells exhibit high-efficiency, fiber-dependent internalization of adenovirus; however, viral capsids have unpredictable immunological effects and are challenging to develop into targeted drug carriers. To exploit this internalization pathway and minimize the use of viral proteins, we developed a simple gene product that self assembles nanoparticles decorated with the knob domain of adenovirus serotype 5 fiber protein. The most significant advantages of this platform include: (i) compatibility with genetic engineering; (ii) no bioconjugate chemistry is required to link fusion proteins to the nanoparticle surface; and (iii) it can direct the reversible assembly of large nanoparticles, which are monodisperse, multivalent, and biodegradable. These particles are predominantly composed from diblock copolymers of elastin-like polypeptide (ELP). ELPs have unique phase transition behavior, whereby they self-assemble above a transition temperature that is simple to control. The diblock ELP described contains two motifs with distinct transition temperatures, which assemble nanoparticles at physiological temperatures. Analysis by non-denaturing-PAGE demonstrated that the purified knob-ELP formed trimers or dimers, which is a property of the native knob/fiber protein. Dynamic light scattering indicated that the diblock copolymer, with or without knob, is able to self assemble into nanoparticles ~40 nm in diameter. To examine the functionality of knob-ELP, their uptake was assessed in a hepatocyte cell-line that expresses the receptor for adenovirus serotype 5 fiber and knob, the coxsackievirus and adenovirus receptor (CAR). Both plain ELP and knob-ELP were bound to the outside of hepatocytes; however, the knob-ELP fusion protein exhibits more internalization and localization to lysosomes of hepatocytes. These findings suggest that functional fusion proteins may only minimally influence the assembly temperature and diameter of ELP nanoparticles. These

  3. Switchable elastin-like polypeptides that respond to chemical inducers of dimerization.

    PubMed

    Dhandhukia, Jugal; Weitzhandler, Isaac; Wang, Wan; MacKay, J Andrew

    2013-04-08

    Elastin-like polypeptides (ELPs) are protein polymers that reversibly phase separate in response to increased temperature, pressure, concentration, ionic strength, and molecular weight. If it were possible to engineer their phase separation to respond to specific molecular substrates, ELP fusion proteins might be engineered as biosensors, smart biomaterials, diagnostic imaging agents, and targeted therapies. What has been lacking is a strategy to design ELPs to respond to specific substrates. To address this deficiency, we report that ELP fusion proteins phase separate in response to chemical inducers of dimerization (CID). The rationale is that ELP phase separation depends on molecular weight, concentration, and local hydrophobicity; therefore, processes that affect these properties, including noncovalent dimerization, can be tuned to produce isothermal phase separation. To test this hypothesis, constructs were evaluated consisting of an immunophilin: human FK-506 binding protein 12 (FKBP) attached to an ELP. Under stoichiometric binding of a CID, the fusion protein homodimerizes and triggers phase separation. This dimerization is reversible upon saturation with excess CID or competitive binding of a small lipophilic macrolide to FKBP. By modulating the ELP molecular weight, phase separation was tuned for isothermal response to CID at physiological ionic strength and temperature (37 °C). To interpret the relationship between transition temperature and equilibrium binding constants, an empirical mathematical model was employed. To the best of our knowledge, this report is the first demonstration of reversible ELP switching in response to controlled dimerization. Due to its simplicity, this strategy may be useful to design ELP fusion proteins that respond to specific dimeric biological entities.

  4. Characterization of cell surface polypeptides of unfertilized, fertilized, and protease-treated zona-free mouse eggs

    SciTech Connect

    Boldt, J.; Gunter, L.E.; Howe, A.M. )

    1989-05-01

    The polypeptide composition of unfertilized, fertilized, and protease-treated zona-free mouse eggs was evaluated in this study. Zona-free eggs were radioiodinated by an Iodogen-catalyzed reaction. Light microscopic autoradiography of egg sections revealed that labeling was restricted to the cell surface. Labeled eggs were solubilized, and cell surface polypeptides were identified by one-dimensional SDS polyacrylamide gel electrophoresis and autoradiography. The unfertilized egg demonstrated 8-10 peptides that incorporated {sup 125}I, with major bands observed at approximately 145-150, 94, and 23 kilodaltons (kD). Zona-free eggs fertilized in vitro and then radiolabeled demonstrated several new bands in comparison to unfertilized eggs, with a major band appearing at approximately 36 kD. Treatment of radiolabeled unfertilized eggs with either trypsin or chymotrypsin (1 mg/ml for 5-20 min) caused enzyme-specific modifications in labeled polypeptides. Trypsin (T) treatment resulted in time-dependant modification of the three major peptides at 145-150, 94, and 23 kD. Chymotrypsin (CT) treatment, in contrast, was associated with loss or modification of the 94 kD band, with no apparent effect on either the 145-150 or 23 kD band. Taken together with previous data indicating that T or CT egg treatment interferes with sperm-egg attachment and fusion, these results suggest a possible role for the 94 kD protein in sperm-egg interaction.

  5. The Fusion Energy Option

    NASA Astrophysics Data System (ADS)

    Dean, Stephen O.

    2004-06-01

    Presentations from a Fusion Power Associates symposium, The Fusion Energy Option, are summarized. The topics include perspectives on fossil fuel reserves, fusion as a source for hydrogen production, status and plans for the development of inertial fusion, planning for the construction of the International Thermonuclear Experimental Reactor, status and promise of alternate approaches to fusion and the need for R&D now on fusion technologies.

  6. Surface active complexes formed between keratin polypeptides and ionic surfactants.

    PubMed

    Pan, Fang; Lu, Zhiming; Tucker, Ian; Hosking, Sarah; Petkov, Jordan; Lu, Jian R

    2016-12-15

    Keratins are a group of important proteins in skin and hair and as biomaterials they can provide desirable properties such as strength, biocompatibility, and moisture regaining and retaining. The aim of this work is to develop water-soluble keratin polypeptides from sheep wool and then explore how their surface adsorption behaves with and without surfactants. Successful preparation of keratin samples was demonstrated by identification of the key components from gel electrophoresis and the reproducible production of gram scale samples with and without SDS (sodium dodecylsulphate) during wool fibre dissolution. SDS micelles could reduce the formation of disulphide bonds between keratins during extraction, reducing inter-molecular crosslinking and improving keratin polypeptide solubility. However, Zeta potential measurements of the two polypeptide batches demonstrated almost identical pH dependent surface charge distributions with isoelectric points around pH 3.5, showing complete removal of SDS during purification by dialysis. In spite of different solubility from the two batches of keratin samples prepared, very similar adsorption and aggregation behavior was revealed from surface tension measurements and dynamic light scattering. Mixing of keratin polypeptides with SDS and C12TAB (dodecyltrimethylammonium bromide) led to the formation of keratin-surfactant complexes that were substantially more effective at reducing surface tension than the polypeptides alone, showing great promise in the delivery of keratin polypeptides via the surface active complexes. Neutron reflection measurements revealed the coexistence of surfactant and keratin polypeptides at the interface, thus providing the structural support to the observed surface tension changes associated with the formation of the surface active complexes.

  7. Revitalizing Fusion via Fission Fusion

    NASA Astrophysics Data System (ADS)

    Manheimer, Wallace

    2001-10-01

    Existing tokamaks could generate significant nuclear fuel. TFTR, operating steady state with DT might generate enough fuel for a 300 MW nuclear reactor. The immediate goals of the magnetic fusion program would necessarily shift from a study of advanced plasma regimes in larger sized devices, to mostly known plasmas regimes, but at steady state or high duty cycle operation in DT plasmas. The science and engineering of breeding blankets would be equally important. Follow on projects could possibly produce nuclear fuel in large quantity at low price. Although today there is strong opposition to nuclear power in the United States, in a 21st century world of 10 billion people, all of whom will demand a middle class life style, nuclear energy will be important. Concern over greenhouse gases will also drive the world toward nuclear power. There are studies indicating that the world will need 10 TW of carbon free energy by 2050. It is difficult to see how this can be achieved without the breeding of nuclear fuel. By using the thorium cycle, proliferation risks are minimized. [1], [2]. 1 W. Manheimer, Fusion Technology, 36, 1, 1999, 2.W. Manheimer, Physics and Society, v 29, #3, p5, July, 2000

  8. Sugar-nucleotide-binding and autoglycosylating polypeptide(s) from nasturtium fruit: biochemical capacities and potential functions.

    PubMed

    Faik, A; Desveaux, D; MacLachlan, G

    2000-05-01

    Polypeptide assemblies cross-linked by S-S bonds (molecular mass>200 kDa) and single polypeptides folded with internal S-S cross-links (<41 kDa) have been detected by SDS/PAGE in particulate membranes and soluble extracts of developing cotyledons of nasturtium (Tropaeolum majus L.). When first prepared from fruit homogenates, these polypeptides were found to bind reversibly to UDP-Gal (labelled with [(14)C]Gal or [(3)H]uridine), and to co-precipitate specifically with added xyloglucan from solutions made with 67% ethanol. Initially, the bound UDP-[(14)C]Gal could be replaced (bumped) by adding excess UDP, or exchanged (chased) with UDP-Gal, -Glc, -Man or -Xyl. However, this capacity for turnover was lost during incubation in reaction media, or during SDS/PAGE under reducing conditions, even as the glycone moiety was conserved by autoglycosylation to form a stable 41 kDa polypeptide. Polyclonal antibodies raised to a similar product purified from Arabidopsis bound to all the labelled nasturtium polypeptides in immunoblotting tests. The antibodies also inhibited the binding of nasturtium polypeptides to UDP-Gal, the uptake of UDP-[(14)C]Gal into intact nasturtium membrane vesicles and the incorporation of [(14)C]Gal into nascent xyloglucan within these vesicles. This is the first direct evidence that these polypeptides facilitate the channelling of UDP-activated sugars from the cytoplasm through Golgi vesicle membranes to lumenal sites, where they can be used as substrates for glycosyltransferases to synthesize products such as xyloglucan.

  9. Interplay between electrophoretic mobility and intrinsic viscosity of polypeptide chains.

    PubMed

    Deiber, Julio A; Peirotti, Marta B; Piaggio, María V

    2012-03-01

    The present work is motivated specifically by the need to find a simple interplay between experimental values of electrophoretic mobility and intrinsic viscosity (IV) of polypeptides. The connection between these two properties, as they are evaluated experimentally in a formulated dilute solution, may provide relevant information concerning the physicochemical characterization and separation of electrically charged chains such as polypeptides. Based on this aspect, a study on the relation between the effective electrophoretic mobility and the IV of the following globular proteins is carried out: bovine carbonic anhydrase, staphylococcal nuclease, human carbonic anhydrase, lysozyme, human serum albumin. The basic interpretation of the IV through polypeptide chain conformations involves two unknowns: one is the Flory characteristic ratio involving short-range intramolecular interactions and the other is the Mark-Houwink exponent associated with large-range intramolecular interactions. Here, it will be shown via basic and well-established electrokinetic theories and scaling concepts that the IV and global chain flexibility of polypeptides in dilute solutions may be estimated from capillary zone electrophoresis, in addition to classical transport properties. The polypeptide local chain flexibility may change due to electrostatic interactions among closer chain ionizing groups and the hindrance effect of their associated structural water.

  10. Effect of detergents on the thermal behavior of elastin-like polypeptides.

    PubMed

    Thapa, Arjun; Han, Wei; Simons, Robin H; Chilkoti, Ashutosh; Chi, Eva Y; López, Gabriel P

    2013-01-01

    Elastin-like polypeptide (ELP) fusions have been designed to allow large-scale, nonchromatographic purification of many soluble proteins by using the inverse transition cycling (ITC) method; however, the sensitivity of the aqueous lower critical solubility phase transition temperature (T(t)) of ELPs to the addition of cosolutes, including detergents, may be a potential hindrance in purification of proteins with surface hydrophobicity in such a manner. To identify detergents that are known to solubilize such proteins (e.g., membrane proteins) and that have little effect on the T(t) of the ELP, we screened a number of detergents with respect to their effects on the T(t) and secondary structures of a model ELP (denoted here as ELP180). We found that mild detergents (e.g., n-dodecyl-β-D-maltoside, Triton-X100, and 3-[(3-cholamidopropyl) dimethylamino]-1-propanesulfonate) do not alter the phase transition behavior or structure (as probed by circular dichroism) of ELP180. This result is in contrast to previous studies that showed a strong effect of other detergents (e.g., sodium dodecylsulfate) on the T(t) of ELPs. Our results clearly indicate that mild detergents do not preclude ITC-based separation of ELPs, and thus that ELP fusions may prove to be useful in the purification of detergent-solubilized recombinant hydrophobic proteins, including membrane proteins, which are otherwise notoriously difficult to extract and purify by conventional separation methods (e.g., chromatography).

  11. Human jagged polypeptide, encoding nucleic acids and methods of use

    DOEpatents

    Li, Linheng; Hood, Leroy

    2000-01-01

    The present invention provides an isolated polypeptide exhibiting substantially the same amino acid sequence as JAGGED, or an active fragment thereof, provided that the polypeptide does not have the amino acid sequence of SEQ ID NO:5 or SEQ ID NO:6. The invention further provides an isolated nucleic acid molecule containing a nucleotide sequence encoding substantially the same amino acid sequence as JAGGED, or an active fragment thereof, provided that the nucleotide sequence does not encode the amino acid sequence of SEQ ID NO:5 or SEQ ID NO:6. Also provided herein is a method of inhibiting differentiation of hematopoietic progenitor cells by contacting the progenitor cells with an isolated JAGGED polypeptide, or active fragment thereof. The invention additionally provides a method of diagnosing Alagille Syndrome in an individual. The method consists of detecting an Alagille Syndrome disease-associated mutation linked to a JAGGED locus.

  12. Polypeptide formation on polar mineral surfaces: possibility of complete chirality

    NASA Astrophysics Data System (ADS)

    Schrader, Malcolm E.

    2017-01-01

    In the present work, it is shown that thermodynamically feasible polymerization of cyanomethanol, which can be formed from formaldehyde and hydrogen cyanide, can lead to synthesis of polypeptides as well as to the previously reported synthesis of RNA. If the polymerization takes place on a one-dimensional feature of a mineral, such as for example a crack on its surface, the concept of quasi-chirality is introduced to describe the adsorbed polypeptide. This, in principle, would lead to formation of proteins that are completely homochiral in their alpha carbon groups. The concept of quasi-chirality can also be introduced in the condensation of glycine under similar conditions to form a polypeptide. This again leads to proteins completely chiral in their alpha carbon groups.

  13. Fusion energy

    NASA Astrophysics Data System (ADS)

    1990-09-01

    The main purpose of the International Thermonuclear Experimental Reactor (ITER) is to develop an experimental fusion reactor through the united efforts of many technologically advanced countries. The ITER terms of reference, issued jointly by the European Community, Japan, the USSR, and the United States, call for an integrated international design activity and constitute the basis of current activities. Joint work on ITER is carried out under the auspices of the International Atomic Energy Agency (IAEA), according to the terms of quadripartite agreement reached between the European Community, Japan, the USSR, and the United States. The site for joint technical work sessions is at the Max Planck Institute of Plasma Physics. Garching, Federal Republic of Germany. The ITER activities have two phases: a definition phase performed in 1988 and the present design phase (1989 to 1990). During the definition phase, a set of ITER technical characteristics and supporting research and development (R and D) activities were developed and reported. The present conceptual design phase of ITER lasts until the end of 1990. The objectives of this phase are to develop the design of ITER, perform a safety and environmental analysis, develop site requirements, define future R and D needs, and estimate cost, manpower, and schedule for construction and operation. A final report will be submitted at the end of 1990. This paper summarizes progress in the ITER program during the 1989 design phase.

  14. Fusion energy

    SciTech Connect

    Not Available

    1990-09-01

    The main purpose of the International Thermonuclear Experimental Reactor (ITER) is to develop an experimental fusion reactor through the united efforts of many technologically advanced countries. The ITER terms of reference, issued jointly by the European Community, Japan, the USSR, and the United States, call for an integrated international design activity and constitute the basis of current activities. Joint work on ITER is carried out under the auspices of the International Atomic Energy Agency (IAEA), according to the terms of quadripartite agreement reached between the European Community, Japan, the USSR, and the United States. The site for joint technical work sessions is at the MaxPlanck Institute of Plasma Physics. Garching, Federal Republic of Germany. The ITER activities have two phases: a definition phase performed in 1988 and the present design phase (1989--1990). During the definition phase, a set of ITER technical characteristics and supporting research and development (R D) activities were developed and reported. The present conceptual design phase of ITER lasts until the end of 1990. The objectives of this phase are to develop the design of ITER, perform a safety and environmental analysis, develop site requirements, define future R D needs, and estimate cost, manpower, and schedule for construction and operation. A final report will be submitted at the end of 1990. This paper summarizes progress in the ITER program during the 1989 design phase.

  15. Atomic Layer Deposition of L-Alanine Polypeptide

    SciTech Connect

    Fu, Yaqin; Li, Binsong; Jiang, Ying-Bing; Dunphy, Darren R.; Tsai, Andy; Tam, Siu-Yue; Fan, Hongyou Y.; Zhang, Hongxia; Rogers, David; Rempe, Susan; Atanassov, Plamen; Cecchi, Joseph L.; Brinker, C. Jeffrey

    2014-10-30

    L-Alanine polypeptide thin films were synthesized via atomic layer deposition (ALD). Rather, instead of using an amino acid monomer as the precursor, an L-alanine amino acid derivatized with a protecting group was used to prevent self-polymerization, increase the vapor pressure, and allow linear cycle-by-cycle growth emblematic of ALD. Moreover, the successful deposition of a conformal polypeptide film has been confirmed by FTIR, TEM, and Mass Spectrometry, and the ALD process has been extended to polyvaline.

  16. Elastin-like polypeptides: biomedical applications of tunable biopolymers.

    PubMed

    MacEwan, Sarah R; Chilkoti, Ashutosh

    2010-01-01

    Artificial repetitive polypeptides have grown in popularity as a bioinspired alternative to synthetic polymers. The genetically encoded synthesis, monodispersity, potential lack of toxicity, and biocompatibility are attractive features of these biopolymers for biological applications. Elastin-like polypeptides (ELPs) are one such class of biopolymers that are of particular interest because of their "smart"-stimuli responsive-properties. Herein, we discuss the genetically encoded design and recombinant synthesis of ELPs that enable precise control of their physicochemical properties and which have led to a wide range of biomedical applications of these biopolymers in the last decade.

  17. Reovirus-specific polypeptides: analysis using discontinuous gel electrophoresis.

    PubMed Central

    Cross, R K; Fields, B N

    1976-01-01

    The electrophoretic analysis of reovirus-specific polypeptides in infected cells using a discontinuous gel system has allowed the resolution of additional viral-specific polypeptides, including one large-sized gamma3 and two (or possibly three) medium-sized (mu3, mu4, mu5(?)) species. The proteins designated mu0, sigma1, and sigma2 based on electrophoretic mobility in gel systems containing phosphate-urea correspond to mu4, sigma2, and sigma1, respectively, when analyzed in systems containing Tris-glycine. It is likely that protein modifications (phosphorylation and glycosylation) are responsible for at least some of these differences. Images PMID:950684

  18. Methods of using viral replicase polynucleotides and polypeptides

    DOEpatents

    Gordon-Kamm, William J.; Lowe, Keith S.; Bailey, Matthew A.; Gregory, Carolyn A.; Hoerster, George J.; Larkins, Brian A.; Dilkes, Brian R.; Burnett, Ronald; Woo, Young Min

    2007-12-18

    The invention provides novel methods of using viral replicase polypeptides and polynucleotides. Included are methods for increasing transformation frequencies, increasing crop yield, providing a positive growth advantage, modulating cell division, transiently modulating cell division, and for providing a means of positive selection.

  19. Review of fusion synfuels

    SciTech Connect

    Fillo, J.A.

    1980-01-01

    Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approx. 40 to 60% and hydrogen production efficiencies by high-temperature electrolysis of approx. 50 to 65% are projected for fusion reactors using high-temperatures blankets. Fusion/coal symbiotic systems appear economically promising for the first generation of commercial fusion synfuels plants. Coal production requirements and the environmental effects of large-scale coal usage would be greatly reduced by a fusion/coal system. In the long term, there could be a gradual transition to an inexhaustible energy system based solely on fusion.

  20. Catalytic and reactive polypeptides and methods for their preparation and use

    DOEpatents

    Schultz, Peter

    1993-01-01

    Catalytic and reactive polypeptides include a binding site specific for a reactant or reactive intermediate involved in a chemical reaction of interest. The polypeptides further include at least one active functionality proximate the bi.

  1. Interfacial energy of polypeptide complex coacervates measured via capillary adhesion.

    PubMed

    Priftis, Dimitrios; Farina, Robert; Tirrell, Matthew

    2012-06-12

    A systematic study of the interfacial energy (γ) of polypeptide complex coacervates in aqueous solution was performed using a surface forces apparatus (SFA). Poly(L-lysine hydrochloride) (PLys) and poly(L-glutamic acid sodium salt) (PGA) were investigated as a model pair of oppositely charged weak polyelectrolytes. These two synthetic polypeptides of natural amino acids have identical backbones and differ only in their charged side groups. All experiments were conducted using equal chain lengths of PLys and PGA in order to isolate and highlight effects of the interactions of the charged groups during complexation. Complex coacervates resulted from mixing very dilute aqueous salt solutions of PLys and PGA. Two phases in equilibrium evolved under the conditions used: a dense polymer-rich coacervate phase and a dilute polymer-deficient aqueous phase. Capillary adhesion, associated with a coacervate meniscus bridge between two mica surfaces, was measured upon the separation of the two surfaces. This adhesion enabled the determination of the γ at the aqueous/coacervate phase interface. Important experimental factors affecting these measurements were varied and are discussed, including the compression force (1.3-35.9 mN/m) and separation speed (2.4-33.2 nm/s). Physical parameters of the system, such as the salt concentration (100-600 mM) and polypeptide chain length (N = 30, 200, and 400) were also studied. The γ of these polypeptide coacervates was separately found to decrease with both increasing salt concentration and decreasing polypeptide chain length. In most of the above cases, γ measurements were found to be very low, <1 mJ/m(2). Biocompatible complex coacervates with low γ have a strong potential for applications in surface coatings, adhesives, and the encapsulation of a wide range of materials.

  2. Repression of gamma-aminobutyric acid type A receptor alpha1 polypeptide biosynthesis requires chronic agonist exposure.

    PubMed

    Miranda, J D; Barnes, E M

    1997-06-27

    Although it is well established that the number of gamma-aminobutyric acid type A (GABAA) receptors declines in cortical neurons exposed to GABAA receptor agonists, the mechanisms responsible for this use-dependent down-regulation remain unclear. Two hypotheses have been proposed: (i) agonist-evoked sequestration and degradation of surface GABAA receptors and (ii) repression of receptor subunit biosynthesis. We have addressed this problem using [35S]Met/Cys pulse-chase labeling of chick cortical neurons in culture and immunoprecipitation and immunoblotting with an antibody (RP4) directed against a GABAA receptor alpha1-(331-381) fusion protein. Exposure of the cells to GABA or isoguvacine for 2 h to 4 days had no effect on the initial rate of 35S incorporation into the GABAA receptor 51-kDa alpha1 polypeptide, but this rate declined by 33% after a 7-day treatment. This is consistent with a previous report (Baumgartner, B. J., Harvey, R. J., Darlison, M. G., and Barnes, E. M. (1994) Mol. Brain Res. 26, 9-17) that a 7-day GABA treatment of this preparation produced a 45% reduction in the alpha1 subunit mRNA level, while a 4-day exposure had no detectable effect. On the other hand, after a 4-day exposure to these agonists, a 30% reduction in the level of the alpha1 polypeptide was observed on immunoblots, similar to that found previously for down-regulation of GABAA receptor ligand-binding sites. Thus, the de novo synthesis of GABAA receptor alpha1 subunits is subject to a delayed use-dependent repression that was observed after, rather than before, the decline in neuronal levels of the polypeptide. Pulse-chase experiments showed a monophasic degradation of the GABAA receptor 35S-alpha1 subunit with a t1/2 = 7.7 h, a process that was unaffected by the addition of GABA to neurons during the chase period. These nascent 35S-labeled polypeptides are presumably diluted into the neuronal pool of unlabeled unassembled alpha1 subunits, which was found to exceed by a 4:1 molar

  3. Fusion Proteins for Half-Life Extension of Biologics as a Strategy to Make Biobetters.

    PubMed

    Strohl, William R

    2015-08-01

    The purpose of making a "biobetter" biologic is to improve on the salient characteristics of a known biologic for which there is, minimally, clinical proof of concept or, maximally, marketed product data. There already are several examples in which second-generation or biobetter biologics have been generated by improving the pharmacokinetic properties of an innovative drug, including Neulasta(®) [a PEGylated, longer-half-life version of Neupogen(®) (filgrastim)] and Aranesp(®) [a longer-half-life version of Epogen(®) (epoetin-α)]. This review describes the use of protein fusion technologies such as Fc fusion proteins, fusion to human serum albumin, fusion to carboxy-terminal peptide, and other polypeptide fusion approaches to make biobetter drugs with more desirable pharmacokinetic profiles.

  4. Proteolysis of ankyrin and of band 3 protein in chemically induced cell fusion. Ca2+ is not mandatory for fusion.

    PubMed Central

    Lang, R D; Wickenden, C; Wynne, J; Lucy, J A

    1984-01-01

    Human erythrocytes were fused by incubation with 0.5-2 mM-chlorpromazine hydrochloride at pH 6.8-7.6. Fusogenic preparations of chlorpromazine were cloudy suspensions of microdroplets, and below pH 6.8 chlorpromazine gave clear solutions that were inactive. Unlike control cells, the lateral mobility of the intramembranous particles of the PF-fracture face of chlorpromazine-treated cells was relatively unrestricted, since the particles were partly clustered at 37 degrees C and they exhibited extensive cold-induced clustering. Ca2+ stimulated fusion, but fusion was only very weakly inhibited by EGTA (10 mM) and by N-ethylmaleimide (50 mM); pretreatment of the cells with Tos-Lys-CH2Cl (7-amino-1-chloro-3-L-tosylamidoheptan-2-one) (7.5 mM) markedly inhibited fusion. Changes in the membrane proteins of erythrocytes fused by chlorpromazine, before and after treatment with chymotrypsin to remove band 3 protein, were investigated. The several observations made indicate that the Ca2+-insensitive component of fusion is associated with degradation of ankyrin (band 2.1 protein) to band 2.3-2.6 proteins and to smaller polypeptides by a serine proteinase that is inhibited by Tos-Lys-CH2Cl, and that the component of fusion inhibited by EGTA and N-ethylmaleimide is associated with degradation of band 3 protein to band 4.5 protein by a Ca2+-activated cysteine proteinase. Proteolysis of ankyrin appeared to be sufficient to permit the chlorpromazine-induced fusion of human erythrocytes, but fusion occurred more rapidly when band 3 protein was also degraded in the presence of Ca2+. Since other cells have structures comparable with the spectrin-actin skeleton of the erythrocyte membrane, the observations reported may be relevant to the initiation of naturally occurring fusion reactions in biomembranes. It is also suggested that, should polypeptides with fusogenic properties be produced from integral and skeletal membrane proteins by endogenous proteolysis, their formation would provide

  5. Characterization of HCoV-229E fusion core: Implications for structure basis of coronavirus membrane fusion

    SciTech Connect

    Liu Cheng; Feng Youjun; Gao Feng; Zhang Qiangmin; Wang Ming . E-mail: vetdean@cau.edu.cn

    2006-07-07

    Human coronavirus 229E (HCoV-229E), a member of group I coronaviruses, has been identified as one of the major viral agents causing respiratory tract diseases in humans for nearly 40 years. However, the detailed molecular mechanism of the membrane fusion mediated by the spike (S) protein of HCoV-229E remains elusive. Here, we report, for the first time, a rationally designed fusion core of HCoV-229E (HR1-SGGRGG-HR2), which was in vitro produced in GST prokaryotic expression system. Multiple lines of experimental data including gel-filtration, chemical cross-linking, and circular diagram (CD) demonstrated that the HCoV-229E fusion core possesses the typical properties of the trimer of coiled-coil heterodimer (six {alpha}-helix bundle). 3D structure modeling presents its most-likely structure, similar to those of coronaviruses that have been well-documented. Collectively, HCoV-229E S protein belongs to the type I fusion protein, which is characterized by the existence of two heptad-repeat regions (HR1 and HR2), furthermore, the available knowledge concerning HCoV-229E fusion core may make it possible to design small molecule or polypeptide drugs targeting the membrane fusion, a crucial step of HCoV-229E infection.

  6. Polypeptides having beta-glucosidase activity and polynucleotides encoding the same

    DOEpatents

    Brown, Kimberly; Harris, Paul

    2013-12-17

    The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  7. Polypeptides having beta-glucosidase activity and beta-xylosidase activity and polynucleotides encoding same

    SciTech Connect

    Morant, Marc Dominique

    2014-05-06

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  8. Polypeptides having beta-glucosidase activity and beta-xylosidase activity and polynucleotides encoding same

    SciTech Connect

    Morant, Marc Dominique

    2014-04-29

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  9. Polypeptides having beta-glucosidase and beta-xylosidase activity and polynucleotides encoding same

    SciTech Connect

    Morant, Marc Dominique

    2014-05-06

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  10. Viral membrane fusion.

    PubMed

    Harrison, Stephen C

    2015-05-01

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a "fusion loop" or "fusion peptide") engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics.

  11. Viral membrane fusion

    PubMed Central

    Harrison, Stephen C.

    2015-01-01

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a “fusion loop” or “fusion peptide”) engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics. PMID:25866377

  12. Cold fusion research

    SciTech Connect

    1989-11-01

    I am pleased to forward to you the Final Report of the Cold Fusion Panel. This report reviews the current status of cold fusion and includes major chapters on Calorimetry and Excess Heat, Fusion Products and Materials Characterization. In addition, the report makes a number of conclusions and recommendations, as requested by the Secretary of Energy.

  13. Magneto-Inertial Fusion

    SciTech Connect

    Wurden, G. A.; Hsu, S. C.; Intrator, T. P.; Grabowski, T. C.; Degnan, J. H.; Domonkos, M.; Turchi, P. J.; Campbell, E. M.; Sinars, D. B.; Herrmann, M. C.; Betti, R.; Bauer, B. S.; Lindemuth, I. R.; Siemon, R. E.; Miller, R. L.; Laberge, M.; Delage, M.

    2015-11-17

    In this community white paper, we describe an approach to achieving fusion which employs a hybrid of elements from the traditional magnetic and inertial fusion concepts, called magneto-inertial fusion (MIF). The status of MIF research in North America at multiple institutions is summarized including recent progress, research opportunities, and future plans.

  14. Magnetized target fusion and fusion propulsion

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, Ronald C.

    2002-01-01

    Magnetized target fusion (MTF) is a thermonuclear fusion concept that is intermediate between the two mainline approaches, magnetic confinement and inertial confinement fusion (MCF and ICF). MTF incorporates some aspects of each and offers advantages over each of the mainline approaches. First, it provides a means of reducing the driver power requirements, thereby admitting a wider range of drivers than ICF. Second, the magnetic field is only used for insulation, not confinement, and the plasma is wall confined, so that plasma instabilities are traded in for hydrodynamic instabilities. However, the degree of compression required to reach fusion condition is lower than for ICF, so that hydrodynamic instabilities are much less threatening. The standoff driver innovation proposes to dynamically form the target plasma and a gaseous shell that compresses and confines the target plasma. Therefore, fusion target fabrication is traded in for a multiplicity of plasma guns, which must work in synchrony. The standoff driver embodiment of MTF leads to a fusion propulsion system concept that is potentially compact and lightweight. We will discuss the underlying physics of MTF and some of the details of the fusion propulsion concept using the standoff driver approach. We discuss here the optimization of an MTF target design for space propulsion. .

  15. Compositions and methods for making selenocysteine containing polypeptides

    DOEpatents

    Soll, Dieter; Aldag, Caroline; Hohn, Michael

    2016-10-11

    Non-naturally occurring tRNA.sup.Sec and methods of using them for recombinant expression of proteins engineered to include one or more selenocysteine residues are disclosed. The non-naturally occurring tRNA.sup.Sec can be used for recombinant manufacture of selenocysteine containing polypeptides encoded by mRNA without the requirement of an SECIS element. In some embodiments, selenocysteine containing polypeptides are manufactured by co-expressing a non-naturally occurring tRNA.sup.Sec a recombinant expression system, such as E. coli, with SerRS, EF-Tu, SelA, or PSTK and SepSecS, and an mRNA with at least one codon that recognizes the anticodon of the non-naturally occurring tRNA.sup.Sec.

  16. The geometry of the ribosomal polypeptide exit tunnel.

    PubMed

    Voss, N R; Gerstein, M; Steitz, T A; Moore, P B

    2006-07-21

    The geometry of the polypeptide exit tunnel has been determined using the crystal structure of the large ribosomal subunit from Haloarcula marismortui. The tunnel is a component of a much larger, interconnected system of channels accessible to solvent that permeates the subunit and is connected to the exterior at many points. Since water and other small molecules can diffuse into and out of the tunnel along many different trajectories, the large subunit cannot be part of the seal that keeps ions from passing through the ribosome-translocon complex. The structure referred to as the tunnel is the only passage in the solvent channel system that is both large enough to accommodate nascent peptides, and that traverses the particle. For objects of that size, it is effectively an unbranched tube connecting the peptidyl transferase center of the large subunit and the site where nascent peptides emerge. At no point is the tunnel big enough to accommodate folded polypeptides larger than alpha-helices.

  17. Imparting large macroscopic changes with small changes in polypeptide composition

    NASA Astrophysics Data System (ADS)

    Sing, Michelle; McKinley, Gareth; Olsen, Bradley

    Block copolymers composed of polypeptides provide an excellent platform for exploring the underlying physics surrounding macroscopic associative network behavior. Previous work in our group has elucidated a difference in the mechanical properties of two nearly identical elastin-like polypeptide (ELP) endblocks. In poly(ELP)s, this substitution is known to result in tighter beta turns. These beta turns exhibit slower responses to changes in temperature within the material. Under shear, the modulus for the alanine-containing ELP triblock is almost three times higher than the glycine-containing ELP. Additionally, preliminary tensile tests show higher stress and strain at break for the alanine ELP triblock. We are able to explain the reasons for this behavior using a variety of spectroscopic and analytical techniques. Small angle neutron and x-ray scattering indicate differences in ordering between the alanine and glycine containing ELP materials both in shear and in stagnant flow.

  18. An engineered coiled-coil polypeptide assembled onto quantum dots for targeted cell imaging

    NASA Astrophysics Data System (ADS)

    Yao, Ming-Hao; Yang, Jie; Song, Ji-Tao; Zhang, Lin; Fang, Bi-Yun; Zhao, Dong-Hui; Xia, Rui-Xue; Jin, Rui-Mei; Zhao, Yuan-Di; Liu, Bo

    2015-12-01

    Quantum dot (QD)-polypeptide probes have been developed through the specific metal-affinity interaction between polypeptides appended with N-terminal polyhistidine sequences and CdSe/ZnS core-shell QDs. The size and charge of a QD-polypeptide can be tuned by using different coiled-coil polypeptides. Compared to glutathione-capped QDs (QD-GSH), QD-polypeptide probes showed an approximately two- to three-fold luminescence increase, and the luminescence increase was not obviously related to the charge of the polypeptide. QD-polypeptide probes with different charge have a great effect on nonspecific cellular uptake. QD-polypeptide probes with negative charge exhibited lower nonspecific cellular uptake in comparison to the QD-GSH, while positively charged QD-polypeptide probes presented higher cellular uptake than the QD-GSH. A targeted QD-ARGD probe can obviously increase targeted cellular uptake in α v β 3 overexpressing HeLa cells compared to QD-A. In addition, QD-polypeptide probes showed lower in vitro cytotoxicity compared to the original QDs. These results demonstrate that these QD-polypeptide probes with high specific cellular uptake, high fluorescence intensity and low background noise are expected to have great potential applications in targeted cell imaging.

  19. Enhanced phospholipase C-gamma1 activity produced by association of independently expressed X and Y domain polypeptides.

    PubMed Central

    Horstman, D A; DeStefano, K; Carpenter, G

    1996-01-01

    The X and Y domains of phospholipase C (PLC)-gamma1, which are conserved in all mammalian phosphoinositide-specific PLC isoforms and are proposed to interact to form the catalytic site, have been expressed as individual hexahistidine-tagged fusion proteins in the baculovirus system. Following coinfection of insect cells with recombinant viruses, association of X and Y polypeptides was demonstrated in coprecipitation assays. When enzyme activity was examined, neither domain possessed catalytic activity when expressed alone; however, coexpression of the X and Y polypeptides produced a functional enzyme. This reconstituted phospholipase activity remained completely dependent on the presence of free Ca2+. The specific activity of the X:Y complex was significantly greater (20- to 100-fold) than that of holoPLC-gamma1 and was only moderately influenced by varying the concentration of substrate. The enzyme activities of holoPLC-gamma1 and the X:Y complex exhibited distinct pH optima. For holoPLC-gamma1 maximal activity was detected at pH 5.0, while activity of the X:Y complex was maximal at pH 7.2. Images Fig. 1 PMID:8755506

  20. Viral membrane fusion

    SciTech Connect

    Harrison, Stephen C.

    2015-05-15

    Membrane fusion is an essential step when enveloped viruses enter cells. Lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. Despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. Stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they undergo a series of conformational changes. A hydrophobic segment (a “fusion loop” or “fusion peptide”) engages the target-cell membrane and collapse of the bridging intermediate thus formed draws the two membranes (virus and cell) together. We know of three structural classes for viral fusion proteins. Structures for both pre- and postfusion conformations of illustrate the beginning and end points of a process that can be probed by single-virion measurements of fusion kinetics. - Highlights: • Viral fusion proteins overcome the high energy barrier to lipid bilayer merger. • Different molecular structures but the same catalytic mechanism. • Review describes properties of three known fusion-protein structural classes. • Single-virion fusion experiments elucidate mechanism.

  1. Polypeptide synthesis induced in Nicotiana clevelandii protoplasts by infection with raspberry ringspot nepovirus.

    PubMed

    Acosta, O; Mayo, M A

    1993-01-01

    Infection of Nicotiana clevelandii protoplasts by raspberry ringspot nepovirus resulted in the accumulation of about 24 polypeptides that differed in M(r) and pI from polypeptides accumulating in mock-inoculated protoplasts. Similar polypeptides accumulated in protoplasts infected with the S and E strains of RRV but different infection-specific polypeptides were detected in protoplasts infected with tobacco ringspot nepovirus. The M(r) of RRV-specific polypeptides ranged from 210,000 to 18,000 and most are presumed to be derived from others by proteolytic cleavage. No evidence was found for marked changes in polypeptide abundance with time after inoculation or for any virus-specific polypeptide becoming disproportionately abundant in the medium during culture.

  2. Separation and nanoencapsulation of antitumor polypeptide from Spirulina platensis.

    PubMed

    Zhang, Bochao; Zhang, Xuewu

    2013-01-01

    Spirulina platensis is a multicellular edible blue-green alga with abundant proteins (∼ 60%). No report is available on the antitumor polypeptides from the whole proteins of S. platensis. In this study, for the first time, an antitumor polypeptide Y2 from trypsin digest of S. platensis proteins was obtained by using freeze-thawing plus ultrasonication extraction, hydrolysis with four enzymes (trypsin, alcalase, papain, and pepsin), and gel filtration chromatography. The results showed that the degree of hydrolysis can be ordered as: trypsin (38.5%) > alcalase (31.2%) > papain (27.8%) > pepsin (7.1%). For MCF-7 and HepG2 cells, at 250 µg/mL, the maximum inhibitory rate of Y2 was 97%, while standard drug 5-FU was 55 and 97%, respectively. Furthermore, the nanoencapsulation of Y2 with chitosan (CS) was also investigated. After nanoencapsulation, the maximum encapsulation efficiency and polypeptides contents are 49 and 15%, respectively; and the antitumor activity is basically not lost. These data demonstrated the potential of nanopolypeptides (Y2-CS) in food and pharmaceutical applications.

  3. Chirality-mediated polypeptide micelles for regulated drug delivery.

    PubMed

    Ding, Jianxun; Li, Chen; Zhang, Ying; Xu, Weiguo; Wang, Jincheng; Chen, Xuesi

    2015-01-01

    Two kinds of triblock poly(ethylene glycol)-polyleucine (PEG-PLeu) copolymers were synthesized through the ring-opening polymerization of L-Leu N-carboxyanhydride (NCA), or equivalent D-Leu NCA and L-Leu NCA with amino-terminated PEG as a macroinitiator. The amphiphilic copolymers spontaneously self-assembled into spherical micellar aggregations in an aqueous environment. The micelle with a racemic polypeptide core exhibited smaller critical micelle concentration and diameter compared to those with a levorotatory polypeptide core. A model anthracycline antineoplastic agent, i.e., doxorubicin (DOX), was loaded into micelles through nanoprecipitation, and the PEG-P(D,L-Leu) micelle exhibited higher drug-loading efficacy than that with a P(L-Leu) core-this difference was attributed to the flexible and compact P(L-Leu) core. Sustained in vitro DOX release from micelles with both levorotatory and racemic polypeptide cores was observed, and the DOX-loaded PEG-P(D,L-Leu) micelle exhibited a slower release rate. More interestingly, DOX-loaded micelles exhibited chirality-mediated antitumor efficacy in vitro and in vivo, which are all better than that of free DOX. Furthermore, both enhanced tumor inhibition and excellent security in vivo were confirmed by histopathological or in situ cell apoptosis analyses. Therefore, DOX-loaded PEG-PLeu micelles appear to be an interesting nanoscale polymeric formulation for promising malignancy chemotherapy.

  4. Polypeptide Chirality Influences Multilayer Thin Film Growth and Structure

    NASA Astrophysics Data System (ADS)

    Bell, Zephra; Khadka, Dhan; Haynie, Donald

    2011-03-01

    Polypeptide multilayer thin films are being developed for a variety of applications.These include coatings for implant devices and systems for drug delivery in thebiomedical sciences, and optical coatings. Subsequent polymer adsorption steps involve polymers of opposite polarity. Here, the polymers were polypeptides. This project compared the consequences of changing polypeptide chirality on film growth and structure. The peptides were poly(L-glutamic acid), its right-handed counterpart, poly(D-glutamic acid), and poly(lysine-tyrosine). The first two are negatively charged at neutral pH, the third one is positively charged. Poly(lysine-tyrosine)/poly(L-glutamic acid) films and poly(lysine-tyrosine)/poly(D-glutamic acid) films werefabricated on 1 mm-thick quartz plates. In one experiment, films were grown to 34layers. The UV absorption spectrum was taken after each layer deposited to determinethe rate of polymer self-assembly. Separately, UV or visible wavelength spectra wereobtained for films stained with a dye cooled/heated in the range 4-65 °C. In anotherexperiment, a mixture of poly-L-glutamic acid and poly-D-glutamic acid was used as thepolyanion for film buildup. The data show that poly(lysine-tyrosine)/poly(L-glutamicacid) films built up at a higher rate than the corresponding right-handed films.

  5. ThPOD3, a truncated polypeptide from Tamarix hispida, conferred drought tolerance in Escherichia coli.

    PubMed

    Guo, Xiao-Hong; Jiang, Jing; Wang, Bai-Chen; Li, Hui-Yu; Wang, Yu-Cheng; Yang, Chuan-Ping; Liu, Gui-Feng

    2010-03-01

    The ThPOD1 gene encodes a peroxidase and was isolated from a Tamarix hispida NaCl-stress root cDNA library. We found that ThPOD1 expression could be induced by abiotic stresses such as cold, salt, drought and exogenous abscisic acid. These findings suggested that ThPOD1 might be involved in the plant response to environmental stresses and ABA treatment. To elucidate the function of this gene, recombinant plasmids expressing full-length ThPOD1 as well as ThPOD2 (aa 41-337), and ThPOD3 (aa 73-337) truncated polypeptides were constructed. SDS-PAGE and Western blot analyses of the fusion proteins revealed that the molecular weights of ThPOD1, ThPOD2 and ThPOD3 were approximately 57, approximately 50 and approximately 47 kDa, respectively. Stress assays of E. coli treated with the recombinant plasmids indicated that ThPOD3 could improve resistance to drought stress. This finding could potentially be used to improve plant tolerance to drought stress via gene transfer.

  6. Linker polypeptides of the phycobilisome from the cyanobacterium Mastigocladus laminosus. I. Isolation and characterization of phycobiliprotein-linker-polypeptide complexes.

    PubMed

    Füglistaller, P; Suter, F; Zuber, H

    1986-07-01

    Phycobilisomes from the cyanobacterium Mastigocladus laminosus cultured in white and red light were isolated and compared with respect to the phycoerythrocyanin (PEC) and linker polypeptide contents. It was verified that the production of PEC is induced by low light intensities. A PEC complex, (alpha PEC beta PEC)6LR34.5,PEC, and a phycocyanin (PC) complex, (alpha PC beta PC)6LR34.5,PC, were isolated from phycobilisomes by Cellex-D anion exchange chromatography and sucrose density gradient centrifugation. The absorption and fluorescence emission maxima of the PEC complex are at 575 and 620 nm and those of the PC complex are at 631 and 647 nm, respectively. The extinction coefficients of the two complexes were determined. From different experiments it was concluded that PEC is present as a hexameric complex, (alpha PEC beta PEC)6LR34.5,PEC, in the phycobilisome. The two linker polypeptides LR34.5,PEC and LR34.5,PC were isolated from their phycobiliprotein complexes by gel filtration on Bio-Gel P-100 in 50% formic acid. A 5-kDa terminal segment of both linker polypeptides was found to influence the hexamer formation of the phycobiliproteins. The same segments have been described to be responsible for the hexamer-hexamer linkage (Yu, M.-H. & Glazer, A.N. (1982) J. Biol. Chem. 257, 3429-3433). A 8.9-kDa linker polypeptide, LR(C)8.9, was isolated from a PEC fraction of the Cellex-D column by Bio-Gel P-100 gel filtration in 50% formic acid. Localisation of this protein within the phycobilisome was attempted. Its most probable function is to terminate the phycobilisomal rods at the end distal to the allophycocyanin core.

  7. Self-association and modification of a genetically engineered polypeptide

    NASA Astrophysics Data System (ADS)

    Top, Ayben

    A genetically synthesized polypeptide and polyethylene glycol (5 kDa or 10 kDa) functionalized forms of its alanine-rich helical domain were characterized. The polypeptide composed of an N-terminal histidine tag, and an alanine-rich domain, denoted as 17H6, has a sequence of: MGH10 SSGHIHM(AAAQEAAAAQAAAQAEAAQAAQ)6AGGYGGMG. 17H6 was originally designed as a scaffold to investigate multivalent interactions after glycosylation through reactive glutamic acid residues. We speculated that the protonation of the glutamic acid residues in these sequences would afford facile opportunities to manipulate their folding and assembly behavior considering the beta-sheet propensities of similar polypeptides at acidic pH. Thus, in the first part of this study, thermal unfolding, reversible self-association, and irreversible aggregation of 17H6 were investigated. Dynamic light scattering, and thermal unfolding measurements indicate that 17H6 spontaneously and reversibly self-associates at an acidic pH and ambient temperature. The resulting multimers have an average hydrodynamic radius of ˜ 10-20 nm and reversibly dissociate to monomers upon an increase to pH 7.4. Both free monomer and 17H6 chains within the multimers are beta-helical and folded at ambient and sub-ambient temperatures. Reversible unfolding of the monomer occurs upon heating of solutions at pH 7.4. At pH 2.3, heating first causes incomplete dissociation and unfolding of the constituent chains. Further incubation at an elevated temperature (80°C) induces additional structural and morphological changes and results in fibrils with a beta-sheet structure and a width of 5-10 nm (7 nm mean) as observed via transmission electron microscopy (TEM). In the second part, the histidine tag, which imparts solubility to the alanine-rich domain at acidic pH was cleaved. Propionaldehyde-functionalized poly(ethylene glycol) (PEG) molecules (5 kDa or 10 kDa) were attached to the N-terminus of the cleaved polypeptide, c17H6, as a

  8. Proteolytic processing of poliovirus polypeptides: antibodies to polypeptide P3-7c inhibit cleavage at glutamine-glycine pairs

    SciTech Connect

    Hanecak, R.; Semler, B.L.; Anderson, C.W.; Wimmer, E.

    1982-07-01

    Proteolytic processing of poliovirus polypeptides was examined by the addition of antibodies directed against the viral proteins P3-7c and P2-X to a cell-free translation extract prepared from infected HeLa cells. Antisera to P3-7c specifically inhibited in vitro processing at Gln-Gly pairs. Partial amino acid sequence analysis revealed a second Tyr-Gly pair that is utilized in protein processing. Neither Tyr-Gly cleavage is affected by antibody to P3-7C. Anti-P3-7c antibodies react not only with P3-7c but also with P3-6a and P3-2, two viral polypeptides NH/sub 2/-coterminal with P3-7c. Preimmune and anti-P2-X antibodies had no effect on the processing of poliovirus proteins in vitro. The authors conclude that the activity responsible for processing poliovirus polypeptides at Gln-Gly pairs resides in the primary structure of P3-7c and not in P2-X.

  9. Materials research for fusion

    NASA Astrophysics Data System (ADS)

    Knaster, J.; Moeslang, A.; Muroga, T.

    2016-05-01

    Fusion materials research started in the early 1970s following the observation of the degradation of irradiated materials used in the first commercial fission reactors. The technological challenges of fusion energy are intimately linked with the availability of suitable materials capable of reliably withstanding the extremely severe operational conditions of fusion reactors. Although fission and fusion materials exhibit common features, fusion materials research is broader. The harder mono-energetic spectrum associated with the deuterium-tritium fusion neutrons (14.1 MeV compared to <2 MeV on average for fission neutrons) releases significant amounts of hydrogen and helium as transmutation products that might lead to a (at present undetermined) degradation of structural materials after a few years of operation. Overcoming the historical lack of a fusion-relevant neutron source for materials testing is an essential pending step in fusion roadmaps. Structural materials development, together with research on functional materials capable of sustaining unprecedented power densities during plasma operation in a fusion reactor, have been the subject of decades of worldwide research efforts underpinning the present maturity of the fusion materials research programme.

  10. A Novel Family in Medicago truncatula Consisting of More Than 300 Nodule-Specific Genes Coding for Small, Secreted Polypeptides with Conserved Cysteine Motifs1[w

    PubMed Central

    Mergaert, Peter; Nikovics, Krisztina; Kelemen, Zsolt; Maunoury, Nicolas; Vaubert, Danièle; Kondorosi, Adam; Kondorosi, Eva

    2003-01-01

    Transcriptome analysis of Medicago truncatula nodules has led to the discovery of a gene family named NCR (nodule-specific cysteine rich) with more than 300 members. The encoded polypeptides were short (60–90 amino acids), carried a conserved signal peptide, and, except for a conserved cysteine motif, displayed otherwise extensive sequence divergence. Family members were found in pea (Pisum sativum), broad bean (Vicia faba), white clover (Trifolium repens), and Galega orientalis but not in other plants, including other legumes, suggesting that the family might be specific for galegoid legumes forming indeterminate nodules. Gene expression of all family members was restricted to nodules except for two, also expressed in mycorrhizal roots. NCR genes exhibited distinct temporal and spatial expression patterns in nodules and, thus, were coupled to different stages of development. The signal peptide targeted the polypeptides in the secretory pathway, as shown by green fluorescent protein fusions expressed in onion (Allium cepa) epidermal cells. Coregulation of certain NCR genes with genes coding for a potentially secreted calmodulin-like protein and for a signal peptide peptidase suggests a concerted action in nodule development. Potential functions of the NCR polypeptides in cell-to-cell signaling and creation of a defense system are discussed. PMID:12746522

  11. Muon Catalyzed Fusion

    NASA Technical Reports Server (NTRS)

    Armour, Edward A.G.

    2007-01-01

    Muon catalyzed fusion is a process in which a negatively charged muon combines with two nuclei of isotopes of hydrogen, e.g, a proton and a deuteron or a deuteron and a triton, to form a muonic molecular ion in which the binding is so tight that nuclear fusion occurs. The muon is normally released after fusion has taken place and so can catalyze further fusions. As the muon has a mean lifetime of 2.2 microseconds, this is the maximum period over which a muon can participate in this process. This article gives an outline of the history of muon catalyzed fusion from 1947, when it was first realised that such a process might occur, to the present day. It includes a description of the contribution that Drachrnan has made to the theory of muon catalyzed fusion and the influence this has had on the author's research.

  12. Magnetic fusion reactor economics

    SciTech Connect

    Krakowski, R.A.

    1995-12-01

    An almost primordial trend in the conversion and use of energy is an increased complexity and cost of conversion systems designed to utilize cheaper and more-abundant fuels; this trend is exemplified by the progression fossil fission {yields} fusion. The present projections of the latter indicate that capital costs of the fusion ``burner`` far exceed any commensurate savings associated with the cheapest and most-abundant of fuels. These projections suggest competitive fusion power only if internal costs associate with the use of fossil or fission fuels emerge to make them either uneconomic, unacceptable, or both with respect to expensive fusion systems. This ``implementation-by-default`` plan for fusion is re-examined by identifying in general terms fusion power-plant embodiments that might compete favorably under conditions where internal costs (both economic and environmental) of fossil and/or fission are not as great as is needed to justify the contemporary vision for fusion power. Competitive fusion power in this context will require a significant broadening of an overly focused program to explore the physics and simbiotic technologies leading to more compact, simplified, and efficient plasma-confinement configurations that reside at the heart of an attractive fusion power plant.

  13. Magnetic-confinement fusion

    NASA Astrophysics Data System (ADS)

    Ongena, J.; Koch, R.; Wolf, R.; Zohm, H.

    2016-05-01

    Our modern society requires environmentally friendly solutions for energy production. Energy can be released not only from the fission of heavy nuclei but also from the fusion of light nuclei. Nuclear fusion is an important option for a clean and safe solution for our long-term energy needs. The extremely high temperatures required for the fusion reaction are routinely realized in several magnetic-fusion machines. Since the early 1990s, up to 16 MW of fusion power has been released in pulses of a few seconds, corresponding to a power multiplication close to break-even. Our understanding of the very complex behaviour of a magnetized plasma at temperatures between 150 and 200 million °C surrounded by cold walls has also advanced substantially. This steady progress has resulted in the construction of ITER, a fusion device with a planned fusion power output of 500 MW in pulses of 400 s. ITER should provide answers to remaining important questions on the integration of physics and technology, through a full-size demonstration of a tenfold power multiplication, and on nuclear safety aspects. Here we review the basic physics underlying magnetic fusion: past achievements, present efforts and the prospects for future production of electrical energy. We also discuss questions related to the safety, waste management and decommissioning of a future fusion power plant.

  14. Residue length and solvation model dependency of elastinlike polypeptides.

    PubMed

    Bilsel, Mustafa; Arkin, Handan

    2010-05-01

    We have performed exhaustive multicanonical Monte Carlo simulations of elastinlike polypeptides with a chain including amino acids (valine-proline-glycine-valine-glycine)n or in short (VPGVG)n, where n changes from 1 to 4, in order to investigate the thermodynamic and structural properties. To predict the characteristic secondary structure motifs of the molecules, Ramachandran plots were prepared and analyzed as well. In these studies, we utilized a realistic model where the interactions between all types of atoms were taken into account. Effects of solvation were also simulated by using an implicit-solvent model with two commonly used solvation parameter sets and compared with the vacuum case.

  15. Residue length and solvation model dependency of elastinlike polypeptides

    NASA Astrophysics Data System (ADS)

    Bilsel, Mustafa; Arkin, Handan

    2010-05-01

    We have performed exhaustive multicanonical Monte Carlo simulations of elastinlike polypeptides with a chain including amino acids (valine-proline-glycine-valine-glycine)n or in short (VPGVG)n , where n changes from 1 to 4, in order to investigate the thermodynamic and structural properties. To predict the characteristic secondary structure motifs of the molecules, Ramachandran plots were prepared and analyzed as well. In these studies, we utilized a realistic model where the interactions between all types of atoms were taken into account. Effects of solvation were also simulated by using an implicit-solvent model with two commonly used solvation parameter sets and compared with the vacuum case.

  16. Reaction mechanisms in the radiolysis of peptides, polypeptides and proteins

    SciTech Connect

    Garrison, W.M.

    1985-01-01

    The purpose of this review is to bring together and to correlate the wide variety of experimental studies that provide information on the reaction products and reaction mechanisms involved in the radiolysis of peptides, polypeptides and proteins (including chromosomal proteins) in both aqueous and solid-state systems. The comparative radiation chemistry of these systems is developed in terms of specific reactions of the peptide main-chain and the aliphatic, aromatic-unsaturated and sulfur-containing side-chains. Information obtained with the various experimental techniques of product analysis, competition kinetics, spin-trapping, pulse radiolysis and ESR spectroscopy is included. 147 refs.

  17. Polypeptide having or assisting in carbohydrate material degrading activity and uses thereof

    DOEpatents

    Schooneveld-Bergmans, Margot Elisabeth Francoise; Heijne, Wilbert Herman Marie; Los, Alrik Pieter

    2016-02-16

    The invention relates to a polypeptide which comprises the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 76% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 76% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional polypeptide and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  18. Activation of the heat-stable polypeptide of the ATP-dependent proteolytic system.

    PubMed Central

    Ciechanover, A; Heller, H; Katz-Etzion, R; Hershko, A

    1981-01-01

    It had been shown previously that the heat-stable polypeptide of the ATP-dependent proteolytic system of reticulocytes, designated APF-1, forms covalent conjugates with protein substrates in an ATP-requiring process. We now describe an enzyme that carries out the activation by ATP of the polypeptide with pyrophosphate displacement. The formation of AMP-polypeptide and transfer of the polypeptide to a secondary acceptor are suggested by an APF-1 requirement for ATP-PPi and ATP-AMP exchange reactions, respectively. With radiolabeled polypeptide, an ATP-dependent labeling of the enzyme was shown to be by a linkage that is acid stable but is labile to treatment with mild alkali, hydroxylamine, borohydride, or mercuric salts. It therefore appears that the AMP-polypeptide undergoes attack by an -SH group of the enzyme to form a thiolester. PMID:6262770

  19. Cell fusion and nuclear fusion in plants.

    PubMed

    Maruyama, Daisuke; Ohtsu, Mina; Higashiyama, Tetsuya

    2016-12-01

    Eukaryotic cells are surrounded by a plasma membrane and have a large nucleus containing the genomic DNA, which is enclosed by a nuclear envelope consisting of the outer and inner nuclear membranes. Although these membranes maintain the identity of cells, they sometimes fuse to each other, such as to produce a zygote during sexual reproduction or to give rise to other characteristically polyploid tissues. Recent studies have demonstrated that the mechanisms of plasma membrane or nuclear membrane fusion in plants are shared to some extent with those of yeasts and animals, despite the unique features of plant cells including thick cell walls and intercellular connections. Here, we summarize the key factors in the fusion of these membranes during plant reproduction, and also focus on "non-gametic cell fusion," which was thought to be rare in plant tissue, in which each cell is separated by a cell wall.

  20. Controlled Nuclear Fusion.

    ERIC Educational Resources Information Center

    Glasstone, Samuel

    This publication is one of a series of information booklets for the general public published by The United States Atomic Energy Commission. Among the topics discussed are: Importance of Fusion Energy; Conditions for Nuclear Fusion; Thermonuclear Reactions in Plasmas; Plasma Confinement by Magnetic Fields; Experiments With Plasmas; High-Temperature…

  1. Antiproton catalyzed fusion

    SciTech Connect

    Morgan, D.L. Jr.; Perkins, L.J.; Haney, S.W.

    1995-05-15

    Because of the potential application to power production, it is important to investigate a wide range of possible means to achieve nuclear fusion, even those that may appear initially to be infeasible. In antiproton catalyzed fusion, the negative antiproton shields the repulsion between the positively charged nuclei of hydrogen isotopes, thus allowing a much higher level of penetration through the repulsive Coulomb barrier, and thereby greatly enhancing the fusion cross section. Because of their more compact wave function, the more massive antiprotons offer considerably more shielding than do negative muons. The effects of the shielding on fusion cross sections are most predominate, at low energies. If the antiproton could exist in the ground state with a nucleus for a sufficient time without annihilating, the fusion cross sections are so enhanced that at room temperature energies, values up to about 1,000 barns (that for d+t) would be possible. Unfortunately, the cross section for antiproton annihilation with the incoming nucleus is even higher. A model that provides an upper bound for the fusion to annihilation cross section for all relevant energies indicates that each antiproton will catalyze no more than about one fusion. Because the energy required to make one antiproton greatly exceeds the fusion energy that is released, this level of catalysis is far from adequate for power production.

  2. Fusion Science Education Outreach

    NASA Astrophysics Data System (ADS)

    Danielson, C. A.; DIII-D Education Group

    1996-11-01

    This presentation will focus on education outreach activities at General Atomics that have been expanded to include the general population on science education with a focus on fusion energy. Outreach materials are distributed upon request both nationally and internationally. These materials include a notebook containing copies of DIII--D tour panels, fusion poster, new fusion energy video, new fusion energy brochure, and the electromagnetic spectrum curriculum. The 1996 Fusion Forum (held in the House Caucus Room) included a student/ teacher lunch with Energy Secretary Hazel O'Leary and a private visit to the Forum exhibits. The continuing partnership with Kearny High School includes lectures, job shadowing, internship, equipment donations and an award-winning electric car-racing program. Development of distribution by CD of the existing interactive fusion energy kiosk and a virtual reality tour of the DIII--D facility are underway. The DIII--D fusion education WWW site includes e-mail addresses to ``Ask the Wizard,'' and/or receive GA's outreach materials. Steve Rodecker, a local science teacher, aided by DIII--D fusion staff, won his second Tapestry Award; he also was named the ``1995 National Science Teacher of the Year'' and will be present to share his experiences with the DIII--D educational outreach program.

  3. Two Horizons of Fusion

    ERIC Educational Resources Information Center

    Lo, Mun Ling; Chik, Pakey Pui Man

    2016-01-01

    In this paper, we aim to differentiate the internal and external horizons of "fusion." "Fusion" in the internal horizon relates to the structure and meaning of the object of learning as experienced by the learner. It clarifies the interrelationships among an object's critical features and aspects. It also illuminates the…

  4. Fusion Power Deployment

    SciTech Connect

    J.A. Schmidt; J.M. Ogden

    2002-02-06

    Fusion power plants could be part of a future portfolio of non-carbon dioxide producing energy supplies such as wind, solar, biomass, advanced fission power, and fossil energy with carbon dioxide sequestration. In this paper, we discuss key issues that could impact fusion energy deployment during the last half of this century. These include geographic issues such as resource availability, scale issues, energy storage requirements, and waste issues. The resource needs and waste production associated with fusion deployment in the U.S. should not pose serious problems. One important feature of fusion power is the fact that a fusion power plant should be locatable within most local or regional electrical distribution systems. For this reason, fusion power plants should not increase the burden of long distance power transmission to our distribution system. In contrast to fusion power, regional factors could play an important role in the deployment of renewable resources such as wind, solar and biomass or fossil energy with CO2 sequestration. We examine the role of these regional factors and their implications for fusion power deployment.

  5. Self-assembly of polypeptide-based copolymers into diverse aggregates.

    PubMed

    Cai, Chunhua; Wang, Liquan; Lin, Jiaping

    2011-10-28

    Recently, increasing attention has been given to the self-assembly behavior of polypeptide-based copolymers. Polypeptides can serve as either shell-forming or core-forming blocks in the formation of various aggregates. The solubility and rigidity of polypeptide blocks have been found to have a profound effect on the self-assembly behavior of polypeptide-based copolymers. Polypeptide graft copolymers combine the advantages of a grafting strategy and the characteristics of polypeptide chains and their self-assembly behavior can be easily adjusted by choosing different polymer chains and copolymer architectures. Fabricating hierarchical structures is one of the attractive topics of self-assembly research of polypeptide copolymers. These hierarchical structures are promising for use in preparing functional materials and, thus, attract increasing attention. Computer simulations have emerged as powerful tools to investigate the self-assembly behavior of polymers, such as polypeptides. These simulations not only support the experimental results, but also provide information that cannot be directly obtained from experiments. In this feature article, recent advances in both experimental and simulation studies for the self-assembly behavior of polypeptide-based copolymers are reviewed.

  6. Compositions comprising a polypeptide having cellulolytic enhancing activity and a bicycle compound and uses thereof

    DOEpatents

    Xu, Feng; Sweeney, Matthew; Quinlan, Jason

    2015-06-16

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a bicyclic compound. The present invention also relates to methods of using the compositions.

  7. Compositions comprising a polypeptide having cellulolytic enhancing activity and a bicyclic compound and uses thereof

    DOEpatents

    Quinlan, Jason; Xu, Feng; Sweeney, Matthew

    2016-10-04

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a bicyclic compound. The present invention also relates to methods of using the compositions.

  8. Compositions comprising a polypeptide having cellulolytic enhancing activity and a quinone compound and uses thereof

    DOEpatents

    Quinlan, Jason; Xu, Feng; Sweeney, Matthew

    2016-03-01

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a quinone compound. The present invention also relates to methods of using the compositions.

  9. Compositions comprising a polypeptide having cellulolytic enhancing activity and a heterocyclic compound and uses thereof

    DOEpatents

    Xu, Feng; Sweeney, Matthew; Quinlan, Jason

    2016-08-02

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a heterocyclic compound. The present invention also relates to methods of using the compositions.

  10. Compositions comprising a polypeptide having cellulolytic enhancing activity and a dioxy compound and uses thereof

    DOEpatents

    Sweeney, Matthew; Xu, Feng; Quinlan, Jason

    2016-07-19

    The present invention relates to compositions comprising: a polypeptide having cellulolytic enhancing activity and a dioxy compound. The present invention also relates to methods of using the compositions.

  11. Analysis of the delocalized Raman modes of conformationally disordered polypeptides.

    PubMed Central

    Chen, L X; Strauss, H L; Snyder, R G

    1993-01-01

    Bands associated with delocalized vibrational modes were identified in the isotropic Raman spectra of a series of polyglycine oligomers in aqueous solution as zwitterions and as cations. The dependence of these bands on conformational disorder and chain length was determined. The observed dependence is closely mimicked in spectra calculated for a series of corresponding model polypeptides. The simulated spectra were calculated in a skeletal approximation for ensembles of conformationally disordered chains. As the chain length of the conformationally disordered polypeptides increases, the observed isotropic spectra rapidly approach the spectrum of the infinitely long disordered chain. Convergence is nearly complete at the tripeptide for both the zwitterion and the cation. The stimulated spectra behave in essentially the same way. Convergence to the spectrum of the infinitely long chain is much more rapid for the conformationally disordered polyglycines than for the ordered polyglycines because of the mode localization that results from disorder. In the low-frequency region the bands in the calculated spectra have frequencies that are systematically dependent on chain length. These bands are related to the longitudinal acoustic modes of the ordered chain. PMID:8324189

  12. Structural analysis of photosystem I polypeptides using chemical crosslinking

    NASA Technical Reports Server (NTRS)

    Armbrust, T. S.; Odom, W. R.; Guikema, J. A.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    Thylakoid membranes, obtained from leaves of 14 d soybean (Glycine max L. cv. Williams) plants, were treated with the chemical crosslinkers glutaraldehyde or 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) to investigate the structural organization of photosystem I. Polypeptides were resolved using lithium dodecyl sulfate polyacrylamide gel electrophoresis, and were identified by western blot analysis using a library of polyclonal antibodies specific for photosystem I subunits. An electrophoretic examination of crosslinked thylakoids revealed numerous crosslinked products, using either glutaraldehyde or EDC. However, only a few of these could be identified by western blot analysis using subunit-specific polyclonal antibodies. Several glutaraldehyde dependent crosslinked species were identified. A single band was identified minimally composed of PsaC and PsaD, documenting the close interaction between these two subunits. The most interesting aspect of these studies was a crosslinked species composed of the PsaB subunit observed following EDC treatment of thylakoids. This is either an internally crosslinked species, which will provide structural information concerning the topology of the complex PsaB protein, a linkage with a polypeptide for which we do not yet have an immunological probe, or a masking of epitopes by the EDC linkage at critical locations in the peptide which is linked to PsaB.

  13. Structural analysis of photosystem I polypeptides using chemical crosslinking.

    PubMed

    Armbrust, T S; Odom, W R; Guikema, J A

    1994-07-01

    Thylakoid membranes, obtained from leaves of 14 d soybean (Glycine max L. cv. Williams) plants, were treated with the chemical crosslinkers glutaraldehyde or 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) to investigate the structural organization of photosystem I. Polypeptides were resolved using lithium dodecyl sulfate polyacrylamide gel electrophoresis, and were identified by western blot analysis using a library of polyclonal antibodies specific for photosystem I subunits. An electrophoretic examination of crosslinked thylakoids revealed numerous crosslinked products, using either glutaraldehyde or EDC. However, only a few of these could be identified by western blot analysis using subunit-specific polyclonal antibodies. Several glutaraldehyde dependent crosslinked species were identified. A single band was identified minimally composed of PsaC and PsaD, documenting the close interaction between these two subunits. The most interesting aspect of these studies was a crosslinked species composed of the PsaB subunit observed following EDC treatment of thylakoids. This is either an internally crosslinked species, which will provide structural information concerning the topology of the complex PsaB protein, a linkage with a polypeptide for which we do not yet have an immunological probe, or a masking of epitopes by the EDC linkage at critical locations in the peptide which is linked to PsaB.

  14. Polypeptide profiles of South Indian isolate of Trypanosoma evansi.

    PubMed

    Sivajothi, S; Rayulu, V C; Bhaskar Reddy, B V; Malakondaiah, P; Sreenivasulu, D; Sudhakara Reddy, B

    2016-09-01

    The field isolates of Trypanosoma evansi was collected from the infected cattle and it was propagated in rats. Trypanosoma evansi parasites were separated from the blood of infected rats by using diethylaminoethyl cellulose column chromatography. Whole cell lysate antigen (WCL) was prepared from purified trypanosomes by ultrasonication and centrifugation. The prepared WCL antigen was further purified by 50 % ammonium sulphate precipitation. Protein concentration of WCL antigen of T. evansi was 60 mg/ml. Protein concentration was adjusted to 1.0 mg/ml in PBS, pH 8.0 and stored at -20(0) C.   Polypeptide profiles of WCL antigen of T. evansi was determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis. A total of eight polypeptide bands of the size ranging from 25 to 85 kDa in WCL antigen of T. evansi were obtained. Five prominent bands with molecular weight of 74, 60, 53, 42 and 37 kDa and three light bands with molecular weight of 85, 34 and 25 kDa were observed.

  15. Elastin-like Polypeptides as Models of Intrinsically Disordered Proteins

    PubMed Central

    Roberts, Stefan; Dzuricky, Michael; Chilkoti, Ashutosh

    2015-01-01

    Elastin-like polypeptides (ELPs) are a class of stimuli-responsive biopolymers inspired by the intrinsically disordered domains of tropoelastin that are composed of repeats of the VPGXG pentapeptide motif, where X is a “guest residue”. They undergo a reversible, thermally triggered lower critical solution temperature (LCST) phase transition, which has been utilized for a variety of applications including protein purification, affinity capture, immunoassays, and drug delivery. ELPs have been extensively studied as protein polymers and as biomaterials, but their relationship to other disordered proteins has heretofore not been established. The biophysical properties of ELPs that lend them their unique material behavior are similar to the properties of many intrinsically disordered proteins (IDP). Their low sequence complexity, phase behavior, and elastic properties make them an interesting “minimal” artificial IDP, and the study of ELPs can hence provide insights into the behavior of other more complex IDPs. Motivated by this emerging realization of the similarities between ELPs and IDPs, this review discusses the biophysical properties of ELPs, their biomedical utility, and their relationship to other disordered polypeptide sequences. PMID:26325592

  16. Mechanically Controlled Electron Transfer in a Single-Polypeptide Transistor

    NASA Astrophysics Data System (ADS)

    Sheu, Sheh-Yi; Yang, Dah-Yen

    2017-01-01

    Proteins are of interest in nano-bio electronic devices due to their versatile structures, exquisite functionality and specificity. However, quantum transport measurements produce conflicting results due to technical limitations whereby it is difficult to precisely determine molecular orientation, the nature of the moieties, the presence of the surroundings and the temperature; in such circumstances a better understanding of the protein electron transfer (ET) pathway and the mechanism remains a considerable challenge. Here, we report an approach to mechanically drive polypeptide flip-flop motion to achieve a logic gate with ON and OFF states during protein ET. We have calculated the transmission spectra of the peptide-based molecular junctions and observed the hallmarks of electrical current and conductance. The results indicate that peptide ET follows an NC asymmetric process and depends on the amino acid chirality and α-helical handedness. Electron transmission decreases as the number of water molecules increases, and the ET efficiency and its pathway depend on the type of water-bridged H-bonds. Our results provide a rational mechanism for peptide ET and new perspectives on polypeptides as potential candidates in logic nano devices.

  17. Vibrational neutron spectroscopy of collagen and model polypeptides.

    PubMed Central

    Middendorf, H D; Hayward, R L; Parker, S F; Bradshaw, J; Miller, A

    1995-01-01

    A pulsed source neutron spectrometer has been used to measure vibrational spectra (20-4000 cm-1) of dry and hydrated type I collagen fibers, and of two model polypeptides, polyproline II and (prolyl-prolyl-glycine)10, at temperatures of 30 and 120 K. the collagen spectra provide the first high resolution neutron views of the proton-dominated modes of a protein over a wide energy range from the low frequency phonon region to the rich spectrum of localized high frequency modes. Several bands show a level of fine structure approaching that of optical data. The principal features of the spectra are assigned. A difference spectrum is obtained for protein associated water, which displays an acoustic peak similar to pure ice and a librational band shifted to lower frequency by the influence of the protein. Hydrogen-weighted densities of states are extracted for collagen and the model polypeptides, and compared with published calculations. Proton mean-square displacements are calculated from Debye-Waller factors measured in parallel quasi-elastic neutron-scattering experiments. Combined with the collagen density of states function, these yield an effective mass of 14.5 a.m.u. for the low frequency harmonic oscillators, indicating that the extended atom approximation, which simplifies analyses of low frequency protein dynamics, is appropriate. PMID:8527680

  18. Reversible Deficiency of Antimicrobial Polypeptides in Bacterial Vaginosis

    PubMed Central

    Valore, Erika V.; Wiley, Dorothy J.; Ganz, Tomas

    2006-01-01

    Bacterial vaginosis is a common condition associated with increased risk of sexually transmitted diseases, including human immunodeficiency virus infections. In contrast, vulvovaginal candidiasis has a much weaker association with sexually transmitted diseases. We found that vaginal lavage fluid from women with bacterial vaginosis is deficient in antimicrobial polypeptides and antimicrobial activity compared to fluid from healthy women or women with vulvovaginal candidiasis. Effective treatment normalized the concentrations of antimicrobial polypeptides in both bacterial vaginosis and in vulvovaginal candidiasis, suggesting that the abnormalities were a result of the diseases. Unlike in vulvovaginal candidiasis, the neutrophil attractant chemokine interleukin-8 (IL-8) was not increased in bacterial vaginosis, accounting for low concentrations of neutrophil-derived defensins in vaginal fluid. In organotypic cultures of human vaginal epithelium containing dendritic cells, treatment with Lactobacillus jensenii, a typical vaginal resident, induced the synthesis of IL-8 mRNA and the epithelial human β-defensin-2 mRNA, but a typical bacterial vaginosis pathogen, Gardnerella vaginalis, had no effect. When the two bacteria were combined, Gardnerella vaginalis did not interfere with the immunostimulatory effect of Lactobacillus jensenii. The loss of normal immunostimulatory flora in bacterial vaginosis is thus associated with a local deficiency of multiple innate immune factors, and this deficiency could predispose individuals to sexually transmitted diseases. PMID:16988245

  19. Effects of snake venom polypeptides on central nervous system.

    PubMed

    Osipov, Alexey; Utkin, Yuri

    2012-12-01

    The nervous system is a primary target for animal venoms as the impairment of its function results in the fast and efficient immobilization or death of a prey. There are numerous evidences about effects of crude snake venoms or isolated toxins on peripheral nervous system. However, the data on their interactions with the central nervous system (CNS) are not abundant, as the blood-brain barrier (BBB) impedes penetration of these compounds into brain. This updated review presents the data about interaction of snake venom polypeptides with CNS. Such data will be described according to three main modes of interactions: - Direct in vivo interaction of CNS with venom polypeptides either capable to penetrate BBB or injected into the brain. - In vitro interactions of cell or sub-cellular fractions of CNS with crude venoms or purified toxins. - Indirect effects of snake venoms or their components on functioning of CNS under different conditions. Although the venom components penetrating BBB are not numerous, they seem to be the most suitable candidates for the leads in drug design. The compounds with other modes of action are more abundant and better studied, but the lack of the data about their ability to penetrate BBB may substantially aggravate the potentials for their medical perspectives. Nevertheless, many such compounds are used for research of CNS in vitro. These investigations may give invaluable information for understanding the molecular basis of CNS diseases and thus lay the basis for targeted drug design. This aspect also will be outlined in the review.

  20. Reverse transcriptase activity of an intron encoded polypeptide.

    PubMed Central

    Fassbender, S; Brühl, K H; Ciriacy, M; Kück, U

    1994-01-01

    A number of group II introns from eukaryotic organelles and prokaryotes contain open reading frames for polypeptides with homology to retroviral reverse transcriptases (RTs). We have used the yeast transposon (Ty) system to express ORFs for RTs from eukaryotic organelles. This includes the mitochondrial coxI intron i1 from the fungus Podospora anserina, the plastid petD intron from the alga Scenedesmus obliquus and the mitochondrial RTL gene from the alga Chlamydomonas reinhardtii. The ORFs were fused with the TYA ORF from the yeast retrotransposon Ty to produce virus-like particles in the recipient strains with detectable amounts of the RT-like polypeptides. Analysis of the heterologous gene products revealed biochemical evidence that the P. anserina intron encodes an RNA-directed DNA polymerase with properties typically found for RTs of viral or retrotransposable origin. In vitro assays showed that the intron encoded RT is sensitive to RT inhibitors such as N-ethylmaleimide and dideoxythymidine triphosphate but is insensitive against the DNA polymerase inhibitor aphidicolin. The direct biochemical evidence provided here supports the idea that intron encoded RTs are involved in intron transposition events. Images PMID:7514530

  1. Mechanically Controlled Electron Transfer in a Single-Polypeptide Transistor

    PubMed Central

    Sheu, Sheh-Yi; Yang, Dah-Yen

    2017-01-01

    Proteins are of interest in nano-bio electronic devices due to their versatile structures, exquisite functionality and specificity. However, quantum transport measurements produce conflicting results due to technical limitations whereby it is difficult to precisely determine molecular orientation, the nature of the moieties, the presence of the surroundings and the temperature; in such circumstances a better understanding of the protein electron transfer (ET) pathway and the mechanism remains a considerable challenge. Here, we report an approach to mechanically drive polypeptide flip-flop motion to achieve a logic gate with ON and OFF states during protein ET. We have calculated the transmission spectra of the peptide-based molecular junctions and observed the hallmarks of electrical current and conductance. The results indicate that peptide ET follows an NC asymmetric process and depends on the amino acid chirality and α-helical handedness. Electron transmission decreases as the number of water molecules increases, and the ET efficiency and its pathway depend on the type of water-bridged H-bonds. Our results provide a rational mechanism for peptide ET and new perspectives on polypeptides as potential candidates in logic nano devices. PMID:28051140

  2. Fusion Studies in Japan

    NASA Astrophysics Data System (ADS)

    Ogawa, Yuichi

    2016-05-01

    A new strategic energy plan decided by the Japanese Cabinet in 2014 strongly supports the steady promotion of nuclear fusion development activities, including the ITER project and the Broader Approach activities from the long-term viewpoint. Atomic Energy Commission (AEC) in Japan formulated the Third Phase Basic Program so as to promote an experimental fusion reactor project. In 2005 AEC has reviewed this Program, and discussed on selection and concentration among many projects of fusion reactor development. In addition to the promotion of ITER project, advanced tokamak research by JT-60SA, helical plasma experiment by LHD, FIREX project in laser fusion research and fusion engineering by IFMIF were highly prioritized. Although the basic concept is quite different between tokamak, helical and laser fusion researches, there exist a lot of common features such as plasma physics on 3-D magnetic geometry, high power heat load on plasma facing component and so on. Therefore, a synergetic scenario on fusion reactor development among various plasma confinement concepts would be important.

  3. Particle beam fusion

    SciTech Connect

    1980-12-31

    Today, in keeping with Sandia Laboratories` designation by the Department of Energy as the lead laboratory for the pulsed power approach to fusion, its efforts include major research activities and the construction of new facilities at its Albuquerque site. Additionally, in its capacity as lead laboratory, Sandia coordinates DOE-supported pulsed power fusion work at other government operated laboratories, with industrial contractors, and universities. The beginning of Sandia`s involvement in developing fusion power was an outgrowth of its contributions to the nation`s nuclear weapon program. The Laboratories` work in the early 1960`s emphasized the use of pulsed radiation environments to test the resistance of US nuclear weapons to enemy nuclear bursts. A careful study of options for fusion power indicated that Sandia`s expertise in the pulsed power field could provide a powerful match to ignite fusion fuel. Although creating test environments is an achieved goal of Sandia`s overall program, this work and other military tasks protected by appropriate security regulations will continue, making full use of the same pulsed power technology and accelerators as the fusion-for-energy program. Major goals of Sandia`s fusion program including the following: (1) complete a particle accelerator to deliver sufficient beam energy for igniting fusion targets; (2) obtain net energy gain, this goal would provide fusion energy output in excess of energy stored in the accelerator; (3) develop a technology base for the repetitive ignition of pellets in a power reactor. After accomplishing these goals, the technology will be introduced to the nation`s commercial sector.

  4. Intranasal administration of elastin-like polypeptide for therapeutic delivery to the central nervous system

    PubMed Central

    McGowan, Jeremy WD; Shao, Qingmei; Vig, Parminder JS; Bidwell, Gene L

    2016-01-01

    Bypassing the blood–brain barrier is one of the primary considerations when designing compounds intended to function in the central nervous system (CNS). Intranasal (IN) administration of otherwise blood–brain barrier impermeable molecules can result in high CNS concentrations and low systemic accumulation, indicating that IN administration may be a useful method of delivering therapeutics to the CNS. Elastin-like polypeptide (ELP) is a large, non-immunogenic, highly manipulable biopolymer with extensive evidence supporting its use as a carrier with the ability to improve drug pharmacokinetics and drug targeting. The ability of ELP to reach the CNS via IN administration has been shown previously. Previous studies have also identified the ability of cell penetrating peptides (CPPs) to increase the uptake of molecules in some instances, including via the IN route. Here, we compared and contrasted the biodistribution of ELPs with or without addition of the CPPs Tat or SynB1 via both the IN and intravenous routes. Administration of ELP via the IN route led to significant accumulation in the brain, especially in the olfactory bulbs. When injected intravenously, <3% of the ELP signal was present outside the vascular compartment. This contrasted with IN administration, which resulted in 79% of the fluorescence signal localized outside the vascular space. The fusion of Tat or SynB1 significantly altered the biodistribution of ELP, decreasing the total CNS accumulation following IN administration. The addition of CPPs to ELP increased their retention in the nasal epithelium. These results suggest ELP may represent an effective CNS delivery vector without further modification and that the addition of a CPP significantly influences biodistribution. PMID:27660412

  5. Intranasal administration of elastin-like polypeptide for therapeutic delivery to the central nervous system.

    PubMed

    McGowan, Jeremy Wd; Shao, Qingmei; Vig, Parminder Js; Bidwell, Gene L

    Bypassing the blood-brain barrier is one of the primary considerations when designing compounds intended to function in the central nervous system (CNS). Intranasal (IN) administration of otherwise blood-brain barrier impermeable molecules can result in high CNS concentrations and low systemic accumulation, indicating that IN administration may be a useful method of delivering therapeutics to the CNS. Elastin-like polypeptide (ELP) is a large, non-immunogenic, highly manipulable biopolymer with extensive evidence supporting its use as a carrier with the ability to improve drug pharmacokinetics and drug targeting. The ability of ELP to reach the CNS via IN administration has been shown previously. Previous studies have also identified the ability of cell penetrating peptides (CPPs) to increase the uptake of molecules in some instances, including via the IN route. Here, we compared and contrasted the biodistribution of ELPs with or without addition of the CPPs Tat or SynB1 via both the IN and intravenous routes. Administration of ELP via the IN route led to significant accumulation in the brain, especially in the olfactory bulbs. When injected intravenously, <3% of the ELP signal was present outside the vascular compartment. This contrasted with IN administration, which resulted in 79% of the fluorescence signal localized outside the vascular space. The fusion of Tat or SynB1 significantly altered the biodistribution of ELP, decreasing the total CNS accumulation following IN administration. The addition of CPPs to ELP increased their retention in the nasal epithelium. These results suggest ELP may represent an effective CNS delivery vector without further modification and that the addition of a CPP significantly influences biodistribution.

  6. Spherical torus fusion reactor

    DOEpatents

    Martin Peng, Y.K.M.

    1985-10-03

    The object of this invention is to provide a compact torus fusion reactor with dramatic simplification of plasma confinement design. Another object of this invention is to provide a compact torus fusion reactor with low magnetic field and small aspect ratio stable plasma confinement. In accordance with the principles of this invention there is provided a compact toroidal-type plasma confinement fusion reactor in which only the indispensable components inboard of a tokamak type of plasma confinement region, mainly a current conducting medium which carries electrical current for producing a toroidal magnet confinement field about the toroidal plasma region, are retained.

  7. Fusion for Space Propulsion

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Schafer, Charles (Technical Monitor)

    2001-01-01

    There is little doubt that humans will attempt to explore and develop the solar system in this century. A large amount of energy will be required for accomplishing this. The need for fusion propulsion is discussed. For a propulsion system, there are three important thermodynamical attributes: (1) The absolute amount of energy available, (2) the propellant exhaust velocity, and (3) the jet power per unit mass of the propulsion system (specific power). For human exploration and development of the solar system, propellant exhaust velocity in excess of 100 km/s and specific power in excess of 10 kW/kg are required. Chemical combustion can produce exhaust velocity up to about 5 km/s. Nuclear fission processes typically result in producing energy in the form of heat that needs to be manipulated at temperatures limited by materials to about 2,800 K. Using the energy to heat a hydrogen propellant increases the exhaust velocity by only a factor of about two. Alternatively the energy can be converted into electricity which is then used to accelerate particles to high exhaust velocity. The necessary power conversion and conditioning equipment, however, increases the mass of the propulsion system for the same jet power by more than two orders of magnitude over chemical system, thus greatly limits the thrust-to-weight ratio attainable. The principal advantage of the fission process is that its development is relatively mature and is available right now. If fusion can be developed, fusion appears to have the best of all worlds in terms of propulsion - it can provide the absolute amount, the propellant exhaust velocity, and the high specific jet power. An intermediate step towards pure fusion propulsion is a bimodal system in which a fission reactor is used to provide some of the energy to drive a fusion propulsion unit. The technical issues related to fusion for space propulsion are discussed. The technical priorities for developing and applying fusion for propulsion are

  8. Cloning and characterization of GST fusion tag stabilized large subunit of Escherichia coli acetohydroxyacid synthase I.

    PubMed

    Li, Heng; Liu, Nan; Wang, Wen-Ting; Wang, Ji-Yu; Gao, Wen-Yun

    2016-01-01

    There are three acetohydroxyacid synthase (AHAS, EC 4.1.3.18) isozymes (I, II, and III) in the enterobacteria Escherichia coli among which AHAS I is the most active. Its large subunit (LSU) possesses full catalytic machinery, but is unstable in the absence of the small subunit (SSU). To get applicable LSU of AHAS I, we prepared and characterized in this study the polypeptide as a His-tagged (His-LSU) and a glutathione S-transferase (GST)-tagged (GST-LSU) fusion protein, respectively. The results showed that the His-LSU is unstable, whereas the GST-LSU displays excellent stability. This phenomenon suggests that the GST polypeptide fusion tag could stabilize the target protein when compared with histidine tag. It is the first time that the stabilizing effect of the GST tag was observed. Further characterization of the GST-LSU protein indicated that it possesses the basic functions of AHAS I with a specific activity of 20.8 μmol min(-1) mg(-1) and a Km value for pyruvate of 0.95 mM. These observations imply that introduction of the GST fusion tag to LSU of AHAS I does not affect the function of the protein. The possible reasons that the GST fusion tag could make the LSU stable are initially discussed.

  9. Thymus Polypeptide Preparation Tactivin Restores Learning and Memory in Thymectomied Rats.

    PubMed

    Novoseletskaya, A V; Kiseleva, N M; Zimina, I V; Bystrova, O V; Belova, O V; Inozemtsev, A N; Arion, V Ya; Sergienko, V I

    2015-09-01

    We studied the effects of tactivin and splenic polypeptides on learning and memory of thymectomized animals. In 3-week rats, thymectomy blocked active avoidance conditioning. Injections of tactivin (0.5 mg/kg) during 1 month after surgery restored learning capacity; splenic polypeptides were ineffective.

  10. Nodule-Specific Polypeptides from Effective Alfalfa Root Nodules and from Ineffective Nodules Lacking Nitrogenase 1

    PubMed Central

    Lang-Unnasch, Naomi; Ausubel, Frederick M.

    1985-01-01

    In addition to leghemoglobin, at least nine nodule-specific polypeptides from the alfalfa (Medicago sativa L.)-Rhizobium meliloti symbiosis were identified by immune assay. Some of these polypeptides may be subunits of larger proteins but none appeared to be subunits of the same multimeric protein. All nine of the nodule-specific polypeptides were localized to within the plant cytosol; they were not found in extracts of bacteroids or in the peribacteroid space. At least one of these nodule-specific polypeptides was found to be antigenically related to nodule-specific polypeptides in pea and/or soybean. Ineffective nodules elicited by R. meliloti strains containing mutations in four different genes required for nitrogenase synthesis contained reduced concentrations of leghemoglobin and of several of the nodule-specific polypeptides. Other nodule-specific polypeptides were unaltered or actually enriched in the ineffective nodules. Many of the differences between the ineffective and effective nodules were apparent in nodules harvested shortly after the nodules became visible. These differences were greatly amplified in older nodules. When the four ineffective nodule types were compared to one another, there were clear quantitative differences in the concentrations of several of the nodule-specific polypeptides. These differences suggest that lack of a functional nitrogenase does not have a single direct effect on nodule development. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:16664146

  11. Design of a single-chain polypeptide tetrahedron assembled from coiled-coil segments.

    PubMed

    Gradišar, Helena; Božič, Sabina; Doles, Tibor; Vengust, Damjan; Hafner-Bratkovič, Iva; Mertelj, Alenka; Webb, Ben; Šali, Andrej; Klavžar, Sandi; Jerala, Roman

    2013-06-01

    Protein structures evolved through a complex interplay of cooperative interactions, and it is still very challenging to design new protein folds de novo. Here we present a strategy to design self-assembling polypeptide nanostructured polyhedra based on modularization using orthogonal dimerizing segments. We designed and experimentally demonstrated the formation of the tetrahedron that self-assembles from a single polypeptide chain comprising 12 concatenated coiled coil-forming segments separated by flexible peptide hinges. The path of the polypeptide chain is guided by a defined order of segments that traverse each of the six edges of the tetrahedron exactly twice, forming coiled-coil dimers with their corresponding partners. The coincidence of the polypeptide termini in the same vertex is demonstrated by reconstituting a split fluorescent protein in the polypeptide with the correct tetrahedral topology. Polypeptides with a deleted or scrambled segment order fail to self-assemble correctly. This design platform provides a foundation for constructing new topological polypeptide folds based on the set of orthogonal interacting polypeptide segments.

  12. Expression of Leukemia-Associated Nup98 Fusion Proteins Generates an Aberrant Nuclear Envelope Phenotype

    PubMed Central

    Fahrenkrog, Birthe; Martinelli, Valérie; Nilles, Nadine; Fruhmann, Gernot; Chatel, Guillaume; Juge, Sabine; Sauder, Ursula; Di Giacomo, Danika; Mecucci, Cristina; Schwaller, Jürg

    2016-01-01

    Chromosomal translocations involving the nucleoporin NUP98 have been described in several hematopoietic malignancies, in particular acute myeloid leukemia (AML). In the resulting chimeric proteins, Nup98's N-terminal region is fused to the C-terminal region of about 30 different partners, including homeodomain (HD) transcription factors. While transcriptional targets of distinct Nup98 chimeras related to immortalization are relatively well described, little is known about other potential cellular effects of these fusion proteins. By comparing the sub-nuclear localization of a large number of Nup98 fusions with HD and non-HD partners throughout the cell cycle we found that while all Nup98 chimeras were nuclear during interphase, only Nup98-HD fusion proteins exhibited a characteristic speckled appearance. During mitosis, only Nup98-HD fusions were concentrated on chromosomes. Despite the difference in localization, all tested Nup98 chimera provoked morphological alterations in the nuclear envelope (NE), in particular affecting the nuclear lamina and the lamina-associated polypeptide 2α (LAP2α). Importantly, such aberrations were not only observed in transiently transfected HeLa cells but also in mouse bone marrow cells immortalized by Nup98 fusions and in cells derived from leukemia patients harboring Nup98 fusions. Our findings unravel Nup98 fusion-associated NE alterations that may contribute to leukemogenesis. PMID:27031510

  13. Expression of Leukemia-Associated Nup98 Fusion Proteins Generates an Aberrant Nuclear Envelope Phenotype.

    PubMed

    Fahrenkrog, Birthe; Martinelli, Valérie; Nilles, Nadine; Fruhmann, Gernot; Chatel, Guillaume; Juge, Sabine; Sauder, Ursula; Di Giacomo, Danika; Mecucci, Cristina; Schwaller, Jürg

    2016-01-01

    Chromosomal translocations involving the nucleoporin NUP98 have been described in several hematopoietic malignancies, in particular acute myeloid leukemia (AML). In the resulting chimeric proteins, Nup98's N-terminal region is fused to the C-terminal region of about 30 different partners, including homeodomain (HD) transcription factors. While transcriptional targets of distinct Nup98 chimeras related to immortalization are relatively well described, little is known about other potential cellular effects of these fusion proteins. By comparing the sub-nuclear localization of a large number of Nup98 fusions with HD and non-HD partners throughout the cell cycle we found that while all Nup98 chimeras were nuclear during interphase, only Nup98-HD fusion proteins exhibited a characteristic speckled appearance. During mitosis, only Nup98-HD fusions were concentrated on chromosomes. Despite the difference in localization, all tested Nup98 chimera provoked morphological alterations in the nuclear envelope (NE), in particular affecting the nuclear lamina and the lamina-associated polypeptide 2α (LAP2α). Importantly, such aberrations were not only observed in transiently transfected HeLa cells but also in mouse bone marrow cells immortalized by Nup98 fusions and in cells derived from leukemia patients harboring Nup98 fusions. Our findings unravel Nup98 fusion-associated NE alterations that may contribute to leukemogenesis.

  14. Applications of elastin-like polypeptides in drug delivery

    PubMed Central

    MacEwan, Sarah R; Chilkoti, Ashutosh

    2014-01-01

    Elastin-like polypeptides (ELPs) are biopolymers inspired by human elastin. Their lower critical solution temperature phase transition behavior and biocompatibility make them useful materials for stimulus-responsive applications in biological environments. Due to their genetically encoded design and recombinant synthesis, the sequence and size of ELPs can be exactly defined. These design parameters control the structure and function of the ELP with a precision that is unmatched by synthetic polymers. Due to these attributes, ELPs have been used extensively for drug delivery in a variety of different embodiments—as soluble macromolecular carriers, self-assembled nanoparticles, cross-linked microparticles, or thermally coacervated depots. These ELP systems have been used to deliver biologic therapeutics, radionuclides, and small molecule drugs to a variety of anatomical sites for the treatment of diseases including cancer, type 2 diabetes, osteoarthritis, and neuroinflammation. PMID:24979207

  15. Discovery and Characterization of smORF-Encoded Bioactive Polypeptides

    PubMed Central

    Saghatelian, Alan; Couso, Juan Pablo

    2016-01-01

    Analysis of genomes, transcriptomes, and proteomes reveals the existence of hundreds to thousands of translated, yet non-annotated short open reading frames (small ORFs or smORFs). The discovery of smORFs, and their protein products, smORF-encoded polypeptides (SEPs), reveals a fundamental gap in our knowledge of protein-coding genes. Different studies have identified central roles for smORFs in metabolism, apoptosis, and development. The discovery of these bioactive SEPs emphasizes the functional potential of this unexplored class of biomolecules. Here, we provide an overview of this emerging field and highlight the opportunities for chemical biology to answer fundamental questions about these novel genes. Such studies will provide new insights into the protein-coding potential of genomes and identify functional genes with roles in biology and disease. PMID:26575237

  16. Expansin polynucleotides, related polypeptides and methods of use

    DOEpatents

    Cosgrove, Daniel J.; Wu, Yajun

    2006-02-21

    The present invention relates to beta expansin polypeptides, nucleotide sequences encoding the same and regulatory elements and their use in altering cell wall structure in plants. Nucleic acid constructs comprising a beta expansin sequence operably linked to a promoter, or other regulatory sequence are disclosed as well as vectors, plant cells, plants, and transformed seeds containing such constructs are provided. Methods for the use of such constructs in repressing or inducing expression of a beta expansin sequences in a plant are also provided as well as methods for harvesting transgenic expansin proteins. In addition, methods are provided for inhibiting or improving cell wall structure in plants by repression or induction of expansin sequences in plants.

  17. Identification of antigenically related polypeptides at centrioles and basal bodies.

    PubMed

    Lin, W; Fung, B; Shyamala, M; Kasamatsu, H

    1981-04-01

    An antigen localized at the centriolar region has been identified by indirect immunofluorescence studies in African green monkey kidney, human, hamster, rat, and mouse cells. The antigen consists of two polypeptides of 14,000 and 17,000 daltons. A related antigen is also present at the basal body region in ciliated cells from chicken, cat, mouse, pig, steer, and rabbit trachea and from rabbit fimbria. Immunoelectron microscopy shows that the immunoreactive antigen is indeed located in the region around the basal bodies of ciliated cat tracheal cells. Thus, we have found an antigen that is common to a variety of cell types from many different animal sources and is specifically associated with both centrioles and basal bodies. The possible role of the antigen in differentiation is discussed.

  18. Identification of antigenically related polypeptides at centrioles and basal bodies.

    PubMed Central

    Lin, W; Fung, B; Shyamala, M; Kasamatsu, H

    1981-01-01

    An antigen localized at the centriolar region has been identified by indirect immunofluorescence studies in African green monkey kidney, human, hamster, rat, and mouse cells. The antigen consists of two polypeptides of 14,000 and 17,000 daltons. A related antigen is also present at the basal body region in ciliated cells from chicken, cat, mouse, pig, steer, and rabbit trachea and from rabbit fimbria. Immunoelectron microscopy shows that the immunoreactive antigen is indeed located in the region around the basal bodies of ciliated cat tracheal cells. Thus, we have found an antigen that is common to a variety of cell types from many different animal sources and is specifically associated with both centrioles and basal bodies. The possible role of the antigen in differentiation is discussed. Images PMID:6166008

  19. Hippocampal asymmetry in exploratory behavior to vasoactive intestinal polypeptide.

    PubMed

    Ivanova, Margarita; Ternianov, Alexandar; Belcheva, Stiliana; Tashev, Roman; Negrev, Negrin; Belcheva, Iren

    2008-06-01

    The effects of vasoactive intestinal polypeptide (VIP) microinjected uni- or bilaterally into the CA1 hippocampal area of male Wistar rats at a dose of 10, 50 and 100 ng on exploratory behavior were examined. VIP microinjected bilaterally at a high dose (100 ng) significantly decreased the horizontal movements, while at low doses (10 and 50 ng) had no effect on the exploratory activity. Microinjections of VIP into the left hippocampal CA1 area at doses 50 and 100 ng suppressed the exploratory activity, while right-side VIP administration at a dose 100 ng significantly increased horizontal movements compared to the respective controls. Vertical activity was stimulated only by VIP administered into the right hippocampal CA1 area at the three doses used. Neither bilateral nor left injections of VIP induced changes in the vertical movements. The main finding was the presence of hippocampal asymmetry in exploratory behavior to unilateral microinjections of VIP depending on the dose and the microinjected hemisphere.

  20. [Periodontal regeneration: the use of polypeptide growth factors].

    PubMed

    Di Genio, M; Barone, A; Ramaglia, L; Sbordone, L

    1994-10-01

    Polypeptide growth factors are a class of potent natural biologic mediators which regulate many of the activities of wound healing including cell proliferation, migration and metabolism. Periodontal regeneration is thought to require the migration and proliferation of periodontal ligament cells on the root surface. In fact, repopulation of the detached root surface by cells from periodontal ligament (PDL) is a prerequisite for new attachment formation. Many studies suggested that Polypeptide Growth Factors (PGF) such as Insulin-like Growth Factor I (IGF-I), Platelet Derived Growth Factor (PDGF), Transforming Growth Factor B (TGF-B), Epidermal Growth Factor (EGF), are important mediators of cellular events in wound healing. Studies in vitro analysed the mitogenic effects determined on periodontal ligament cells by growth factors using (3H) Thymidine incorporation during DNA synthesis. The results suggested that recombinant human PDGF and IGF-I stimulate the proliferation of PDL fibroblastic cells and the combination of these growth factors showed a synergistic effect revealing the highest mitogenic effect among all individual growth factors as well as any combination of the growth factors tested. Furthermore these studies demonstrated that rh-PDGF and IGF-I stimulate chemotaxis of PDL fibroblastic cells, and supported a role for TGF-B as a regulator of the mitogenic response to PDGF in these cells. Other studies in vivo showed periodontal tissues regeneration introducing mixtures of recombinant human platelet derived growth factor and insulin-like growth factor into lesions of experimentally induced periodontitis in beagle dogs and monkeys.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Mechanism(s) of heat killing: accumulation of nascent polypeptides in the nucleus?

    PubMed

    Lee, Y J; Borrelli, M J; Corry, P M

    1991-05-15

    To investigate the possibility that nascent polypeptides released from polysomes by heat shock accumulate in the nucleus, cells were pulse labeled with [35S]methionine for two minutes and heated immediately thereafter at 45.5 degrees C for 10 minutes. When isolated nuclei were subjected to gel electrophoresis and subsequently autoradiographed, heated nuclei exhibited an approximately 10-fold increase in radioactive polypeptides in comparison to nonheated controls. These nascent polypeptides were nonspecific molecules covering a wide range of molecular weights. It is plausible that the accumulation of polypeptides in the nucleus results in hyperthermic cytotoxicity. Therefore, we propose that a potential target for heat killing is within the nucleus, at sites where nascent polypeptides accumulate after heat shock.

  2. Laser-Driven Fusion.

    ERIC Educational Resources Information Center

    Gibson, A. F.

    1980-01-01

    Discusses the present status and future prospects of laser-driven fusion. Current research (which is classified under three main headings: laser-matter interaction processes, compression, and laser development) is also presented. (HM)

  3. Viral membrane fusion

    PubMed Central

    Harrison, Stephen C

    2008-01-01

    Infection by viruses having lipid-bilayer envelopes proceeds through fusion of the viral membrane with a membrane of the target cell. Viral ‘fusion proteins’ facilitate this process. They vary greatly in structure, but all seem to have a common mechanism of action, in which a ligand-triggered, large-scale conformational change in the fusion protein is coupled to apposition and merger of the two bilayers. We describe three examples—the influenza virus hemagglutinin, the flavivirus E protein and the vesicular stomatitis virus G protein—in some detail, to illustrate the ways in which different structures have evolved to implement this common mechanism. Fusion inhibitors can be effective antiviral agents. PMID:18596815

  4. Fusion-breeder program

    SciTech Connect

    Moir, R.W.

    1982-11-19

    The various approaches to a combined fusion-fission reactor for the purpose of breeding /sup 239/Pu and /sup 233/U are described. Design aspects and cost estimates for fuel production and electricity generation are discussed. (MOW)

  5. Polypeptides of Treponema pallidum: progress toward understanding their structural, functional, and immunologic roles. Treponema Pallidum Polypeptide Research Group.

    PubMed Central

    Norris, S J

    1993-01-01

    Treponema pallidum subsp. pallidum, the spirochete that causes syphilis, is unusual in a number of respects, including its small genome size, inability to grow under standard in vitro culture conditions, microaerophilism, apparent paucity of outer membrane proteins, structurally complex periplasmic flagella, and ability to evade the host immune responses and cause disease over a period of years to decades. Many of these attributes are related ultimately to its protein content. Our knowledge of the activities, structure, and immunogenicity of its proteins has been expanded by the application of recombinant DNA, hybridoma, and structural fractionation techniques. The purpose of this monograph is to summarize and correlate this new information by using two-dimensional gel electrophoresis, monoclonal antibody reactivity, sequence data, and other properties as the bases of polypeptide identification. The protein profiles of the T. pallidum subspecies causing syphilis, yaws, and endemic syphilis are virtually indistinguishable but differ considerably from those of other treponemal species. Among the most abundant polypeptides are a group of lipoproteins of unknown function that appear to be important in the immune response during syphilitic infection. The periplasmic flagella of T. pallidum and other spirochetes are unique with regard to their protein content and ultrastructure, as well as their periplasmic location. They are composed of three core proteins (homologous to the other members of the eubacterial flagellin family) and a single, unrelated sheath protein; the functional significance of this arrangement is not understood at present. Although the bacterium contains the chaperonins GroEL and DnaK, these proteins are not under the control of the heat shock regulon as they are in most organisms. Studies of the immunogenicity of T. pallidum proteins indicate that many may be useful for immunodiagnosis and immunoprotection. Future goals in T. pallidum polypeptide

  6. Glossary of fusion energy

    NASA Astrophysics Data System (ADS)

    Whitson, M. O.

    1985-02-01

    The Glossary of Fusion Energy is an attempt to present a concise, yet comprehensive collection of terms that may be beneficial to scientists and laymen who are directly or tangentially concerned with this burgeoning energy enterprise. Included are definitions of terms in theoretical plasma physics, controlled thermonuclear fusion, and some related physics concepts. Also, short descriptions of some of the major thermonuclear experiments currently under way in the world today are included.

  7. Cold nuclear fusion

    SciTech Connect

    Tsyganov, E. N.

    2012-02-15

    Recent accelerator experiments on fusion of various elements have clearly demonstrated that the effective cross-sections of these reactions depend on what material the target particle is placed in. In these experiments, there was a significant increase in the probability of interaction when target nuclei are imbedded in a conducting crystal or are a part of it. These experiments open a new perspective on the problem of so-called cold nuclear fusion.

  8. Fusion ignition research experiment

    SciTech Connect

    Dale Meade

    2000-07-18

    Understanding the properties of high gain (alpha-dominated) fusion plasmas in an advanced toroidal configuration is the largest remaining open issue that must be addressed to provide the scientific foundation for an attractive magnetic fusion reactor. The critical parts of this science can be obtained in a compact high field tokamak which is also likely to provide the fastest and least expensive path to understanding alpha-dominated plasmas in advanced toroidal systems.

  9. Ice Growth Inhibition in Antifreeze Polypeptide Solution by Short-Time Solution Preheating

    PubMed Central

    Nishi, Naoto; Miyamoto, Takuya; Waku, Tomonori; Tanaka, Naoki; Hagiwara, Yoshimichi

    2016-01-01

    The objective of this study is to enhance the inhibition of ice growth in the aqueous solution of a polypeptide, which is inspired by winter flounder antifreeze protein. We carried out measurements on unidirectional freezing of the polypeptide solution. The thickness of the solution was 0.02 mm, and the concentration of polypeptide was varied from 0 to 2 mg/mL. We captured successive microscopic images of ice/solution interfaces, and measured the interface velocity from the locations of tips of the pectinate interface in the images. We also simultaneously measured the temperature by using a small thermocouple. The ice/solution interface temperature was defined by the temperature at the tips. It was found that the interface temperature was decreased with an increasing concentration of polypeptide. To try varying the activity of the polypeptide, we preheated the polypeptide solution and cooled it before carrying out the measurements. Preheating for 1–5 hours was found to cause a further decrease in the interface temperature. Furthermore, wider regions of solution and ice with inclined interfaces in the pectinate interface structure were observed, compared with the case where the solution was not preheated. Thus, the ice growth inhibition was enhanced by this preheating. To investigate the reason for this enhancement, we measured the conformation and aggregates of polypeptide in the solution. We also measured the local concentration of polypeptide. It was found that the polypeptide aggregates became larger as a result of preheating, although the polypeptide conformation was unchanged. These large aggregates caused both adsorption to the interface and the wide regions of supercooled solution in the pectinate interface structure. PMID:27152720

  10. Protein-based hydrogels self-assembled from genetically engineered triblock polypeptides containing coiled-coil domains

    NASA Astrophysics Data System (ADS)

    Xu, Chunyu

    Protein-based biomaterials have great potential in biomedical applications due to their similar composition with biological organisms. Environment-sensitive hydrogels based on proteins can undergo sol-gel transition due to the conformational change of the proteins in response to external stimuli. The physical properties of these hydrogels can be tailored by modification of the protein structures. Two major hypotheses were made in this dissertation. One was that coiled-coil folding motifs could be a good candidate for physical crosslinking in protein-based hydrogels, and the other was that the conformational change of coiled-coils in response to external stimuli could mediate the sol-gel transition of the protein-based hydrogels. The first part established synthesis strategies of the coiled-coil containing proteins using a genetic engineering technique. An important observation was made that the fusion sequence on the proteins could influence the thermal stability of the proteins. In the second part of the research, the self-assembly of hydrogels from a series of triblock polypeptides containing coiled-coils was evaluated. It was found that the hydrogels had a porous interconnected network microstructure. The hydrogels responded to temperature and pH, which correlated to the temperature- and pH-triggered structural transition of the coiled-coil domains. In addition, the formation of hydrogels was reversible in the present or absence of guanidine hydrochloride (GdnHCl). The last part of the research attempted to explore the relationship between the structure of the protein polymers and the physical property of the hydrogels, and to investigate the parameters influencing the hydrogel formation and physical properties. Triblock and diblock polypeptides were designed to contain different lengths of coiled-coil domains. Tyrosine residues were incorporated at selected solvent-exposed positions in order to increase the hydrophobicity of the coiled-coil domains. The

  11. Magnetized Target Fusion

    NASA Technical Reports Server (NTRS)

    Griffin, Steven T.

    2002-01-01

    Magnetized target fusion (MTF) is under consideration as a means of building a low mass, high specific impulse, and high thrust propulsion system for interplanetary travel. This unique combination is the result of the generation of a high temperature plasma by the nuclear fusion process. This plasma can then be deflected by magnetic fields to provide thrust. Fusion is initiated by a small traction of the energy generated in the magnetic coils due to the plasma's compression of the magnetic field. The power gain from a fusion reaction is such that inefficiencies due to thermal neutrons and coil losses can be overcome. Since the fusion reaction products are directly used for propulsion and the power to initiate the reaction is directly obtained from the thrust generation, no massive power supply for energy conversion is required. The result should be a low engine mass, high specific impulse and high thrust system. The key is to successfully initiate fusion as a proof-of-principle for this application. Currently MSFC is implementing MTF proof-of-principle experiments. This involves many technical details and ancillary investigations. Of these, selected pertinent issues include the properties, orientation and timing of the plasma guns and the convergence and interface development of the "pusher" plasma. Computer simulations of the target plasma's behavior under compression and the convergence and mixing of the gun plasma are under investigation. This work is to focus on the gun characterization and development as it relates to plasma initiation and repeatability.

  12. ITER Fusion Energy

    ScienceCinema

    Dr. Norbert Holtkamp

    2016-07-12

    ITER (in Latin “the way”) is designed to demonstrate the scientific and technological feasibility of fusion energy. Fusion is the process by which two light atomic nuclei combine to form a heavier over one and thus release energy. In the fusion process two isotopes of hydrogen – deuterium and tritium – fuse together to form a helium atom and a neutron. Thus fusion could provide large scale energy production without greenhouse effects; essentially limitless fuel would be available all over the world. The principal goals of ITER are to generate 500 megawatts of fusion power for periods of 300 to 500 seconds with a fusion power multiplication factor, Q, of at least 10. Q ? 10 (input power 50 MW / output power 500 MW). The ITER Organization was officially established in Cadarache, France, on 24 October 2007. The seven members engaged in the project – China, the European Union, India, Japan, Korea, Russia and the United States – represent more than half the world’s population. The costs for ITER are shared by the seven members. The cost for the construction will be approximately 5.5 billion Euros, a similar amount is foreseen for the twenty-year phase of operation and the subsequent decommissioning.

  13. Domed Silica Microcylinders Coated with Oleophilic Polypeptides and Their Behavior in Lyotropic Cholesteric Liquid Crystals of the Same Polypeptide.

    PubMed

    Rosu, Cornelia; Jacobeen, Shane; Park, Katherine; Reichmanis, Elsa; Yunker, Peter; Russo, Paul S

    2016-12-13

    Liquid crystals can organize dispersed particles into useful and exotic structures. In the case of lyotropic cholesteric polypeptide liquid crystals, polypeptide-coated particles are appealing because the surface chemistry matches that of the polymeric mesogen, which permits a tighter focus on factors such as extended particle shape. The colloidal particles developed here consist of a magnetic and fluorescent cylindrically symmetric silica core with one rounded, almost hemispherical end. Functionalized with helical poly(γ-stearyl-l-glutamate) (PSLG), the particles were dispersed at different concentrations in cholesteric liquid crystals (ChLC) of the same polymer in tetrahydrofuran (THF). Defects introduced by the particles to the director field of the bulk PSLG/THF host led to a variety of phases. In fresh mixtures, the cholesteric mesophase of the PSLG matrix was distorted, as reflected in the absence of the characteristic fingerprint pattern. Over time, the fingerprint pattern returned, more quickly when the concentration of the PSLG-coated particles was low. At low particle concentration the particles were "guided" by the PSLG liquid crystal to organize into patterns similar to that of the re-formed bulk chiral nematic phase. When their concentration increased, the well-dispersed PSLG-coated particles seemed to map onto the distortions in the bulk host's local director field. The particles located near the glass vial-ChLC interfaces were stacked lengthwise into architectures with apparent two-dimensional hexagonal symmetry. The size of these "crystalline" structures increased with particle concentration. They displayed remarkable stability toward an external magnetic field; hydrophobic interactions between the PSLG polymers in the shell and those in the bulk LC matrix may be responsible. The results show that bio-inspired LCs can assemble suitable colloidal particles into soft crystalline structures.

  14. Femtosecond spectroscopy probes the folding quality of antibody fragments expressed as GFP fusions in the cytoplasm

    SciTech Connect

    Didier, P.; Weiss, E.; Sibler, A.-P.; Philibert, P.; Martineau, P.; Bigot, J.-Y.; Guidoni, L.

    2008-02-22

    Time-resolved femtosecond spectroscopy can improve the application of green fluorescent proteins (GFPs) as protein-folding reporters. The study of ultrafast excited-state dynamics (ESD) of GFP fused to single chain variable fragment (scFv) antibody fragments, allowed us to define and measure an empirical parameter that only depends on the folding quality (FQ) of the fusion. This method has been applied to the analysis of genetic fusions expressed in the bacterial cytoplasm and allowed us to distinguish folded and thus functional antibody fragments (high FQ) with respect to misfolded antibody fragments. Moreover, these findings were strongly correlated to the behavior of the same scFvs expressed in animal cells. This method is based on the sensitivity of the ESD to the modifications in the tertiary structure of the GFP induced by the aggregation state of the fusion partner. This approach may be applicable to the study of the FQ of polypeptides over-expressed under reducing conditions.

  15. Peptides and polypeptides as scaffolds for optoelectronics and biomaterials applications

    NASA Astrophysics Data System (ADS)

    Charati, Manoj B.

    Peptides and polypeptides are emerging as a new class of biomaterials due to their unique structural, physiochemical, mechanical, and biological properties. The development of peptide and protein-based biomaterials is driven by the convergence of convenient techniques for peptide/protein engineering and its importance in applications as smart biomaterials. The thesis is divided in two parts; the first part highlights the importance of incorporation of non-natural amino acids into peptides and proteins. In particular, incorporation on p-bromophenylalanine in short alpha-helical peptide templates to control the association of chromophores is discussed. In the second part, design of a multi-component, biocompatible polypeptide with superior elasticity is discussed. Part 1. Novel peptide templates to control association of chromophores. Tailor made peptide and protein materials have many versatile applications, as both conformation and functional group position can be controlled. Such control may have intriguing applications in the development of hybrid materials for electroactive applications. A critical need in fabricating devices from organic semiconducting materials is to achieve control over the conformation and distance between two conjugated chains. Controlling chromophore spacing and orientation with required precision over nanometer length scale poses a greater challenge. Here we propose a peptide based template to control the alignment of the methylstilbene and Oxa-PPV chromophores with desired orientations and spacing. The hybrid peptides were characterized via CD, exciton coupled CD, 1H NMR and photoluminescence experiments. It is observed that slight change in the orientation of molecules has pronounced effect on the photo-physical behavior of the molecules. Characterization of the hybrid peptides via circular dichroism (CD) confirmed the helical character of the designed peptides and indicated that inclusion of non-natural amino acids has significant

  16. Fusion for Space Propulsion

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Schafer, Charles (Technical Monitor)

    2001-01-01

    There is little doubt that humans will attempt to explore and develop the solar system in this century. A large amount of energy will be required for accomplishing this. The need for fusion propulsion is discussed. For a propulsion system, there are three important thermodynamical attributes: (1) The absolute amount of energy available, (2) the propellant exhaust velocity, and (3) the jet power per unit mass of the propulsion system (specific power). For human exploration and development of the solar system, propellant exhaust velocity in excess of 100 km/s and specific power in excess of 10 kW/kg are required. Chemical combustion can produce exhaust velocity up to about 5 km/s. Nuclear fission processes typically result in producing energy in the form of heat that needs to be manipulated at temperatures limited by materials to about 2,800 K. Using the energy to heat a hydrogen propellant increases the exhaust velocity by only a factor of about two. Alternatively the energy can be converted into electricity which is then used to accelerate particles to high exhaust velocity. The necessary power conversion and conditioning equipment, however, increases the mass of the propulsion system for the same jet power by more than two orders of magnitude over chemical system, thus greatly limits the thrust-to-weight ratio attainable. The principal advantage of the fission process is that its development is relatively mature and is available right now. If fusion can be developed, fusion appears to have the best of all worlds in terms of propulsion - it can provide the absolute amount, the propellant exhaust velocity, and the high specific jet power. An intermediate step towards pure fusion propulsion is a bimodal system in which a fission reactor is used to provide some of the energy to drive a fusion propulsion unit. The technical issues related to fusion for space propulsion are discussed. The technical priorities for developing and applying fusion for propulsion are

  17. Multifunctional quantum dot-polypeptide hybrid nanogel for targeted imaging and drug delivery

    NASA Astrophysics Data System (ADS)

    Yang, Jie; Yao, Ming-Hao; Wen, Lang; Song, Ji-Tao; Zhang, Ming-Zhen; Zhao, Yuan-Di; Liu, Bo

    2014-09-01

    A new type of multifunctional quantum dot (QD)-polypeptide hybrid nanogel with targeted imaging and drug delivery properties has been developed by metal-affinity driven self-assembly between artificial polypeptides and CdSe-ZnS core-shell QDs. On the surface of QDs, a tunable sandwich-like microstructure consisting of two hydrophobic layers and one hydrophilic layer between them was verified by capillary electrophoresis, transmission electron microscopy, and dynamic light scattering measurements. Hydrophobic and hydrophilic drugs can be simultaneously loaded in a QD-polypeptide nanogel. In vitro drug release of drug-loaded QD-polypeptide nanogels varies strongly with temperature, pH, and competitors. A drug-loaded QD-polypeptide nanogel with an arginine-glycine-aspartic acid (RGD) motif exhibited efficient receptor-mediated endocytosis in αvβ3 overexpressing HeLa cells but not in the control MCF-7 cells as analyzed by confocal microscopy and flow cytometry. In contrast, non-targeted QD-polypeptide nanogels revealed minimal binding and uptake in HeLa cells. Compared with the original QDs, the QD-polypeptide nanogels showed lower in vitro cytotoxicity for both HeLa cells and NIH 3T3 cells. Furthermore, the cytotoxicity of the targeted QD-polypeptide nanogel was lower for normal NIH 3T3 cells than that for HeLa cancer cells. These results demonstrate that the integration of imaging and drug delivery functions in a single QD-polypeptide nanogel has the potential for application in cancer diagnosis, imaging, and therapy.A new type of multifunctional quantum dot (QD)-polypeptide hybrid nanogel with targeted imaging and drug delivery properties has been developed by metal-affinity driven self-assembly between artificial polypeptides and CdSe-ZnS core-shell QDs. On the surface of QDs, a tunable sandwich-like microstructure consisting of two hydrophobic layers and one hydrophilic layer between them was verified by capillary electrophoresis, transmission electron

  18. Polypeptides and functions of antigens from human coronaviruses 229E and OC43.

    PubMed Central

    Schmidt, O W; Kenny, G E

    1982-01-01

    Coronaviruses possess three major size classes of polypeptides as judged by molecular weight: approximately 180,000, approximately 50,000, and approximately 23,000. Human coronaviruses 229E and OC43 possess not only three similar size classes of polypeptides but also three distinct antigens, none of which cross-react with the heterologous strain. Polypeptides separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were reacted in rocket immunoelectrophoresis with antiserum monospecific to each of the three strain-specific antigens (excised precipitin lines from crossed immunoelectrophoresis profiles were used for immunogens). Monospecific antiserum with neutralizing ability reacted with a polypeptide of 186,000 daltons for 229E and a polypeptide of 190,000 daltons for OC43. The antigen which elicited neutralizing antibody response was located at the surface, associated with the corona of the virion, glycosylated, and bound by concanavalin A. Another less prominent surface antigen was represented by size classes of 23,000 daltons for 229E and 24,000 for OC43. The core antigens of the viruses had molecular weights of 49,000 and 229E and 52,000 and OC43 virus. Thus, the molecular weights and functions of the antigens of human coronaviruses are similar to those of animal coronaviruses. The polypeptides of coronaviruses 229E and OC43 are nearly identical as judged by molecular weight, but the similar polypeptides of the two viruses represent different immunological specificities. Images PMID:6173324

  19. Polypeptide folding-mediated tuning of the optical and structural properties of gold nanoparticle assemblies.

    PubMed

    Aili, Daniel; Gryko, Piotr; Sepulveda, Borja; Dick, John A G; Kirby, Nigel; Heenan, Richard; Baltzer, Lars; Liedberg, Bo; Ryan, Mary P; Stevens, Molly M

    2011-12-14

    Responsive hybrid nanomaterials with well-defined properties are of significant interest for the development of biosensors with additional applications in tissue engineering and drug delivery. Here, we present a detailed characterization using UV-vis spectroscopy and small angle X-ray scattering of a hybrid material comprised of polypeptide-decorated gold nanoparticles with highly controllable assembly properties. The assembly is triggered by a folding-dependent bridging of the particles mediated by the heteroassociation of immobilized helix-loop-helix polypeptides and a complementary nonlinear polypeptide present in solution. The polypeptides are de novo designed to associate and fold into a heterotrimeric complex comprised of two disulfide-linked four-helix bundles. The particles form structured assemblies with a highly defined interparticle gap (4.8±0.4 nm) that correlates to the size of the folded polypeptides. Transitions in particle aggregation dynamics, mass-fractal dimensions and ordering, as a function of particle size and the concentration of the bridging polypeptide, are observed; these have significant effects on the optical properties of the assemblies. The assembly and ordering of the particles are highly complex processes that are affected by a large number of variables including the number of polypeptides bridging the particles and the particle mobility within the aggregates. A fundamental understanding of these processes is of paramount interest for the development of novel hybrid nanomaterials with tunable structural and optical properties and for the optimization of nanoparticle-based colorimetric biodetection strategies.

  20. Myoblast fusion in Drosophila

    SciTech Connect

    Haralalka, Shruti; Abmayr, Susan M.

    2010-11-01

    The body wall musculature of a Drosophila larva is composed of an intricate pattern of 30 segmentally repeated muscle fibers in each abdominal hemisegment. Each muscle fiber has unique spatial and behavioral characteristics that include its location, orientation, epidermal attachment, size and pattern of innervation. Many, if not all, of these properties are dictated by founder cells, which determine the muscle pattern and seed the fusion process. Myofibers are then derived from fusion between a specific founder cell and several fusion competent myoblasts (FCMs) fusing with as few as 3-5 FCMs in the small muscles on the most ventral side of the embryo and as many as 30 FCMs in the larger muscles on the dorsal side of the embryo. The focus of the present review is the formation of the larval muscles in the developing embryo, summarizing the major issues and players in this process. We have attempted to emphasize experimentally-validated details of the mechanism of myoblast fusion and distinguish these from the theoretically possible details that have not yet been confirmed experimentally. We also direct the interested reader to other recent reviews that discuss myoblast fusion in Drosophila, each with their own perspective on the process . With apologies, we use gene nomenclature as specified by Flybase (http://flybase.org) but provide Table 1 with alternative names and references.

  1. Fusion, magnetic confinement

    SciTech Connect

    Berk, H.L.

    1992-08-06

    An overview is presented of the principles of magnetic confinement of plasmas for the purpose of achieving controlled fusion conditions. Sec. 1 discusses the different nuclear fusion reactions which can be exploited in prospective fusion reactors and explains why special technologies need to be developed for the supply of tritium or {sup 3}He, the probable fuels. In Sec. 2 the Lawson condition, a criterion that is a measure of the quality of confinement relative to achieving fusion conditions, is explained. In Sec. 3 fluid equations are used to describe plasma confinement. Specific confinement configurations are considered. In Sec. 4 the orbits of particle sin magneti and electric fields are discussed. In Sec. 5 stability considerations are discussed. It is noted that confinement systems usually need to satisfy stability constraints imposed by ideal magnetohydrodynamic (MHD) theory. The paper culminates with a summary of experimental progress in magnetic confinement. Present experiments in tokamaks have reached the point that the conditions necessary to achieve fusion are being satisfied.

  2. Composition and biosynthesis of thylakoid membrane polypeptides in the red alga Cyanidium caldarium: Comparison with the thylakoid polypeptide composition of higher plants and cyanobacteria.

    PubMed

    Yurina, N P; Karakashev, G V; Karapetyan, N V; Odintsova, M S

    1991-10-01

    The polypeptide composition of thylakoid membranes of the red alga Cyanidium caldarium was studied by PAGE in the presence of lithium dodecyl sulfate. The thylakoid membranes were shown to contain 65 polypeptides with mol wt from 110 to 10 kDa. PS I isolated from C. caldarium cells is composed of at least 5 components, one of which is the chlorophyll-protein complex with mol wt of 110 kDa typical of higher plants. Cyt f, c 552, b 6 and b 559 were identified. Inhibition of carotenoid biosynthesis with norflurazon caused no changes in the polypeptide composition of thylakoid membranes of the algae grown in dark. The suppression of the biosynthesis rate of some thylakoid polypeptides in the algae grown with norflurazon in light is a result of membrane photodestruction. Thylakoid membranes from C. caldarium cells are more similar in the number of protein components to thylakoid membranes from cells of the cyanobacterium Anacystis nidulans than to those of higher plants (Pisum sativum), which was proved by immune-blotting assays: Thylakoid membranes of the red alga and cyanobacteria contain 28 homologous polypeptides, while thylakoid membranes of the alga and pea, only 15.

  3. Characterization of an amidated form of pancreatic polypeptide from the daddy sculpin (Cottus scorpius).

    PubMed

    Conlon, J M; Schmidt, W E; Gallwitz, B; Falkmer, S; Thim, L

    1986-12-30

    The primary structure of pancreatic polypeptide from the teleostean fish, Cottus scorpius (daddy sculpin) was established as: YPPQPESPGGNASPEDWAKYHAAVRHYVNLITRQRYNH2 The presence of a COOH-terminally alpha-amidated amino acid was established using an HPLC method of general applicability. Although the peptide shows strong homology towards anglerfish pancreatic polypeptide (86%), homology towards porcine peptide YY (PYY) (61%) and porcine neuropeptide Y (NPY) (61%) was greater than towards porcine pancreatic polypeptide (PP) (47%). This result supports suggestions that the gene duplication events which led to PP, NPY and PYY formation took place after the time of divergence of fish and mammals.

  4. The polymerization of amino acid adenylates on sodium-montmorillonite with preadsorbed polypeptides

    NASA Technical Reports Server (NTRS)

    Paecht-Horowitz, Mella; Eirich, Frederick R.

    1988-01-01

    The spontaneous polymerization of amino acid adenylates on Na-montmorillonite in dilute, neutral suspension, after polypeptides were adsorbed on the clay, is studied. It is found that the degrees of polymerization of the oligopeptides and polypeptides obtained is dependent on the amounts of polypeptides that were preadsorbed. It is concluded that a catalytic activity may derive from c-spacings that offer adsorption sites for the reagent amino acid adenylate within the peripheral recesses of irregularly stacked clay platelets by bringing the anhydride bonds and neutral amino groups into favorable reaction distances.

  5. The Research on the Impact of Maca Polypeptide on Sport Fatigue.

    PubMed

    Miao, Hua

    2015-01-01

    In order to study the effect of maca polypeptide on sport fatigue, this paper selected 40 male mice, and they were randomly divided into group A, B, C and D. group A, B and C were fed food with different concentrations of maca polypeptide, and group D was control group. After two weeks of feeding, measured physiological indexes of mice, including blood glucose, urea nitrogen and creatinine. At last gived the experimental results, as well as the analysis. Experimental results show that maca polypeptide can improve the ability of anti-fatigue mice, and in a certain concentration range, the higher the concentration, the better the resistance to fatigue.

  6. Fabrication and characterization of non-volatile transistor memory based on polypeptide as gate dielectric

    NASA Astrophysics Data System (ADS)

    Liang, Lijuan; Li, LianFang; Wei, Xianfu; Huang, Beiqing; Wei, Yen

    2017-01-01

    The organic thin film transistor (OTFT) fabricated with the polypeptide as a dielectric layer shows memory function. In order to investigate the effect of polypeptide structure on the performance of non-volatile transistor memory, the Fourier-transform IR (FT- IR) and Circular Dichiroism (CD) spectral of PMLG film has been applied, respectively. In conclusion, the memory transistor device fabricated with polypeptide as the ferroelectric exhibit promising behavior such as a large memory window, and the dipole moment of the amide group was considered as the main source of the memory function.

  7. Peaceful Uses of Fusion

    DOE R&D Accomplishments Database

    Teller, E.

    1958-07-03

    Applications of thermonuclear energy for peaceful and constructive purposes are surveyed. Developments and problems in the release and control of fusion energy are reviewed. It is pointed out that the future of thermonuclear power reactors will depend upon the construction of a machine that produces more electric energy than it consumes. The fuel for thermonuclear reactors is cheap and practically inexhaustible. Thermonuclear reactors produce less dangerous radioactive materials than fission reactors and, when once brought under control, are not as likely to be subject to dangerous excursions. The interaction of the hot plasma with magnetic fields opens the way for the direct production of electricity. It is possible that explosive fusion energy released underground may be harnessed for the production of electricity before the same feat is accomplished in controlled fusion processes. Applications of underground detonations of fission devices in mining and for the enhancement of oil flow in large low-specific-yield formations are also suggested.

  8. Spherical torus fusion reactor

    DOEpatents

    Peng, Yueng-Kay M.

    1989-01-01

    A fusion reactor is provided having a near spherical-shaped plasma with a modest central opening through which straight segments of toroidal field coils extend that carry electrical current for generating a toroidal magnet plasma confinement fields. By retaining only the indispensable components inboard of the plasma torus, principally the cooled toroidal field conductors and in some cases a vacuum containment vessel wall, the fusion reactor features an exceptionally small aspect ratio (typically about 1.5), a naturally elongated plasma cross section without extensive field shaping, requires low strength magnetic containment fields, small size and high beta. These features combine to produce a spherical torus plasma in a unique physics regime which permits compact fusion at low field and modest cost.

  9. Spherical torus fusion reactor

    DOEpatents

    Peng, Yueng-Kay M.

    1989-04-04

    A fusion reactor is provided having a near spherical-shaped plasma with a modest central opening through which straight segments of toroidal field coils extend that carry electrical current for generating a toroidal magnet plasma confinement fields. By retaining only the indispensable components inboard of the plasma torus, principally the cooled toroidal field conductors and in some cases a vacuum containment vessel wall, the fusion reactor features an exceptionally small aspect ratio (typically about 1.5), a naturally elongated plasma cross section without extensive field shaping, requires low strength magnetic containment fields, small size and high beta. These features combine to produce a spherical torus plasma in a unique physics regime which permits compact fusion at low field and modest cost.

  10. Ceramics for fusion applications

    SciTech Connect

    Clinard, F.W. Jr.

    1986-01-01

    Ceramics are required for a variety of uses in both near-term fusion devices and in commercial powerplants. These materials must retain adequate structural and electrical properties under conditions of neutron, particle, and ionizing irradiation; thermal and applied stresses; and physical and chemical sputtering. Ceramics such as Al/sub 2/O/sub 3/, MgAl/sub 2/O/sub 4/, BeO, Si/sub 3/N/sub 4/ and SiC are currently under study for fusion applications, and results to date show widely-varying response to the fusion environment. Materials can be identified today which will meet initial operating requirements, but improvements in physical properties are needed to achieve satisfactory lifetimes for critical applications.

  11. Fusion research at ORNL

    SciTech Connect

    Not Available

    1982-03-01

    The ORNL Fusion Program includes the experimental and theoretical study of two different classes of magnetic confinement schemes - systems with helical magnetic fields, such as the tokamak and stellarator, and the ELMO Bumpy Torus (EBT) class of toroidally linked mirror systems; the development of technologies, including superconducting magnets, neutral atomic beam and radio frequency (rf) heating systems, fueling systems, materials, and diagnostics; the development of databases for atomic physics and radiation effects; the assessment of the environmental impact of magnetic fusion; and the design of advanced demonstration fusion devices. The program involves wide collaboration, both within ORNL and with other institutions. The elements of this program are shown. This document illustrates the program's scope; and aims by reviewing recent progress.

  12. Simulation of Fusion Plasmas

    ScienceCinema

    Holland, Chris [UC San Diego, San Diego, California, United States

    2016-07-12

    The upcoming ITER experiment (www.iter.org) represents the next major milestone in realizing the promise of using nuclear fusion as a commercial energy source, by moving into the “burning plasma” regime where the dominant heat source is the internal fusion reactions. As part of its support for the ITER mission, the US fusion community is actively developing validated predictive models of the behavior of magnetically confined plasmas. In this talk, I will describe how the plasma community is using the latest high performance computing facilities to develop and refine our models of the nonlinear, multiscale plasma dynamics, and how recent advances in experimental diagnostics are allowing us to directly test and validate these models at an unprecedented level.

  13. A SUMO-GROUCHO Q DOMAIN FUSION PROTEIN: CHARACTERIZATION AND IN VIVO ULP1-MEDIATED CLEAVAGE

    PubMed Central

    Kuo, Dennis; Nie, Minghua; De Hoff, Peter; Chambers, Michael; Phillips, Martin; Hirsch, Ann M.; Courey, Albert J.

    2010-01-01

    We describe here a system for the expression and purification of small ubiquitin-related modifier (SUMO) fusion proteins, which often exhibit dramatically increased solubility and stability during expression in bacteria relative to unfused proteins. The vector described here allows expression of a His-tagged protein of interest fused at its N-terminus to SUMO. Using this vector, we have produced a polypeptide consisting of SUMO fused to the Q-domain of Drosophila Groucho in a concentrated soluble form. Hydrodynamic analysis shows that, consistent with previous studies on full-length Groucho, the fusion protein forms an elongated tetramer, as well as higher order oligomers. After expressing a protein as a fusion to SUMO, it is often desirable to cleave the SUMO off of the fusion protein using a SUMO-specific protease such as Ulp1. To facilitate such processing, we have constructed a dual expression vector encoding two fusion proteins: one consisting of SUMO fused to Ulp1 and a second consisting of SUMO fused to a His-tagged protein of interest. The SUMO-Ulp1 cleaves both itself and the other SUMO fusion protein in the bacterial cells prior to lysis, and the proteins retain solubility after cleavage. PMID:20732424

  14. Vasoactive intestinal polypeptide provokes acetylcholine release from the myenteric plexus

    SciTech Connect

    Kusunoki, M.; Tsai, L.H.; Taniyama, K.; Tanaka, C.

    1986-07-01

    Effects of vasoactive intestinal polypeptide (VIP) on the release of acetylcholine (ACh) from longitudinal muscle strips with myenteric plexus (LM) preparations were examined in the guinea pig small intestine. VIP (10 to 10 W M) induced a concentration-dependent contraction of LM preparation. The VIP-induced contractions seem to be related to three components, the scopolamine-sensitive, the scopolamine-insensitive, the tetrodotoxin-sensitive, and the tetrodotoxin-insensitive contractions. VIP (10 to 10 W M) induced a concentration-dependent increase in the release of (TH)ACh from LM preparations preloaded with (TH)choline. The VIP-evoked (TH)ACh release was inhibited by removal of CaS from the perfusion medium and by treatment with tetrodotoxin but not by scopolamine and hexamethonium. The spontaneous and VIP-evoked (TH)ACh release was not affected by phentolamine, propranolol, methysergide, diphenhydramine, cimetidine, bicuculline, or (D-ProS, D-Trp/sup 7,9/)substance P. The result demonstrates that VIP induces contractions of longitudinal smooth muscle directly and indirectly by the stimulation of both cholinergic neurons and noncholinergic excitatory neurons.

  15. Coarse-grained, foldable, physical model of the polypeptide chain

    PubMed Central

    Chakraborty, Promita; Zuckermann, Ronald N.

    2013-01-01

    Although nonflexible, scaled molecular models like Pauling–Corey’s and its descendants have made significant contributions in structural biology research and pedagogy, recent technical advances in 3D printing and electronics make it possible to go one step further in designing physical models of biomacromolecules: to make them conformationally dynamic. We report here the design, construction, and validation of a flexible, scaled, physical model of the polypeptide chain, which accurately reproduces the bond rotational degrees of freedom in the peptide backbone. The coarse-grained backbone model consists of repeating amide and α-carbon units, connected by mechanical bonds (corresponding to φ and ψ) that include realistic barriers to rotation that closely approximate those found at the molecular scale. Longer-range hydrogen-bonding interactions are also incorporated, allowing the chain to readily fold into stable secondary structures. The model is easily constructed with readily obtainable parts and promises to be a tremendous educational aid to the intuitive understanding of chain folding as the basis for macromolecular structure. Furthermore, this physical model can serve as the basis for linking tangible biomacromolecular models directly to the vast array of existing computational tools to provide an enhanced and interactive human–computer interface. PMID:23898168

  16. Aspects of structural landscape of human islet amyloid polypeptide

    NASA Astrophysics Data System (ADS)

    He, Jianfeng; Dai, Jin; Li, Jing; Peng, Xubiao; Niemi, Antti J.

    2015-01-01

    The human islet amyloid polypeptide (hIAPP) co-operates with insulin to maintain glycemic balance. It also constitutes the amyloid plaques that aggregate in the pancreas of type-II diabetic patients. We have performed extensive in silico investigations to analyse the structural landscape of monomeric hIAPP, which is presumed to be intrinsically disordered. For this, we construct from first principles a highly predictive energy function that describes a monomeric hIAPP observed in a nuclear magnetic resonance experiment, as a local energy minimum. We subject our theoretical model of hIAPP to repeated heating and cooling simulations, back and forth between a high temperature regime where the conformation resembles a random walker and a low temperature limit where no thermal motions prevail. We find that the final low temperature conformations display a high level of degeneracy, in a manner which is fully in line with the presumed intrinsically disordered character of hIAPP. In particular, we identify an isolated family of α-helical conformations that might cause the transition to amyloidosis, by nucleation.

  17. Aqueous cholesteric liquid crystals using uncharged rodlike polypeptides.

    PubMed

    Bellomo, Enrico G; Davidson, Patrick; Impéror-Clerc, Marianne; Deming, Timothy J

    2004-07-28

    The aqueous, lyotropic liquid-crystalline phase behavior of the alpha-helical polypeptide, poly(N(epsilon)-2-[2-(2-methoxyethoxy)ethoxy]acetyl-lysine) (1), has been studied using optical microscopy and X-ray scattering. Solutions of optically pure 1 were found to form cholesteric liquid crystals at volume fractions that decreased with increasing average chain length. At very high volume fractions, the formation of a hexagonal mesophase was observed. The pitch of the cholesteric phase could be varied by a mixture of enantiomeric samples L-1 and D-1, where the pitch increased as the mixture approached equimolar. The cholesteric phases could be untwisted, using either magnetic field or shear flow, into nematic phases, which relaxed into cholesterics upon removal of field or shear. We have found that the phase diagram of 1 in aqueous solution parallels that of poly(gamma-benzyl glutamate) in organic solvents, thus providing a useful system for liquid-crystal applications requiring water as solvent.

  18. Parametric sensitivity analysis of avian pancreatic polypeptide (APP).

    PubMed

    Zhang, H; Wong, C F; Thacher, T; Rabitz, H

    1995-10-01

    Computer simulations utilizing a classical force field have been widely used to study biomolecular properties. It is important to identify the key force field parameters or structural groups controlling the molecular properties. In the present paper the sensitivity analysis method is applied to study how various partial charges and solvation parameters affect the equilibrium structure and free energy of avian pancreatic polypeptide (APP). The general shape of APP is characterized by its three principal moments of inertia. A molecular dynamics simulation of APP was carried out with the OPLS/Amber force field and a continuum model of solvation energy. The analysis pinpoints the parameters which have the largest (or smallest) impact on the protein equilibrium structure (i.e., the moments of inertia) or free energy. A display of the protein with its atoms colored according to their sensitivities illustrates the patterns of the interactions responsible for the protein stability. The results suggest that the electrostatic interactions play a more dominant role in protein stability than the part of the solvation effect modeled by the atomic solvation parameters.

  19. Structural organization and polypeptide composition of the avian adenovirus core.

    PubMed Central

    Li, P; Bellett, A J; Parish, C R

    1984-01-01

    CELO virus (fowl adenovirus 1) contained three core polypeptides of molecular weights 20,000, 12,000, and 9,500. The core was similar to that of human adenoviruses, with some evidence of compact subcore domains. Micrococcal nuclease digestion of CELO virus cores produced a smear of DNA fragments of gradually decreasing size, with no nucleosome subunit or repeat pattern. Moreover, when digested cores were analyzed without protease treatment, there was again no evidence of a nucleosome substructure; neither DNA fragments nor core proteins entered a 4% polyacrylamide gel. The organization of the core is thus quite unlike that of chromatin. Restriction endonuclease analysis of the DNA from digested cores showed that the right end was on the outside of the core. We suggest that adenovirus DNA is condensed into the core by cross-linking and neutralization by the core proteins, beginning with the packaging sequence at the center of the core and ending with the right end of the DNA on the outside. Images PMID:6092686

  20. Characterization of a baculovirus gene encoding a small conotoxinlike polypeptide.

    PubMed Central

    Eldridge, R; Li, Y; Miller, L K

    1992-01-01

    We identified a gene of Autographa californica nuclear polyhedrosis virus (AcMNPV) that encodes a small cysteine-rich polypeptide which has size and sequence similarity to omega-conotoxins, a class of calcium ion (Ca2+) channel inhibitors, found in the venom of cone snails. Transcriptional analysis indicated that the 159-bp open reading frame, which we named ctl, and a downstream 984-bp open reading frame are transcribed as a single 1.3-kb bicistronic late RNA. The mature ctl gene product was identified as a small secreted protein by high-pressure liquid chromatography fractionation of extracellular fluid. Viruses with a site-specific deletion in ctl appeared normal with regard to the kinetics and virulence of infection, both in vitro and in vivo. Although we studied the behavior of wild-type and mutant virus-infected insects in some detail, a biological role for ctl in AcMNPV infection remains to be established. Images PMID:1404603

  1. Aspects of structural landscape of human islet amyloid polypeptide

    SciTech Connect

    He, Jianfeng Dai, Jin; Li, Jing; Peng, Xubiao; Niemi, Antti J.

    2015-01-28

    The human islet amyloid polypeptide (hIAPP) co-operates with insulin to maintain glycemic balance. It also constitutes the amyloid plaques that aggregate in the pancreas of type-II diabetic patients. We have performed extensive in silico investigations to analyse the structural landscape of monomeric hIAPP, which is presumed to be intrinsically disordered. For this, we construct from first principles a highly predictive energy function that describes a monomeric hIAPP observed in a nuclear magnetic resonance experiment, as a local energy minimum. We subject our theoretical model of hIAPP to repeated heating and cooling simulations, back and forth between a high temperature regime where the conformation resembles a random walker and a low temperature limit where no thermal motions prevail. We find that the final low temperature conformations display a high level of degeneracy, in a manner which is fully in line with the presumed intrinsically disordered character of hIAPP. In particular, we identify an isolated family of α-helical conformations that might cause the transition to amyloidosis, by nucleation.

  2. Vasoactive intestinal polypeptide entrains circadian rhythms in astrocytes

    PubMed Central

    Marpegan, Luciano; Krall, Thomas J.; Herzog, Erik D.

    2009-01-01

    Many mammalian cell types show daily rhythms in gene expression driven by a circadian pacemaker. For example, cultured astrocytes display circadian rhythms in Period1 and Period2 expression. It is not known, however, how or which intercellular factors synchronize and sustain rhythmicity in astrocytes. Because astrocytes are highly sensitive to vasoactive intestinal polypeptide (VIP), a neuropeptide released by neurons and important for the coordination of daily cycling, we hypothesized that VIP entrains circadian rhythms in astrocytes. We used astrocyte cultures derived from knock-in mice containing a bioluminescent reporter of PERIOD2 (PER2) protein, to assess the effects of VIP on the rhythmic properties of astrocytes. VIP induced a dose-dependent increase in the peak-to-trough amplitude of the ensemble rhythms of PER2 expression with maximal effects near 100nM VIP and threshold values between 0.1 and 1 nM. VIP also induced dose- and phase-dependent shifts in PER2 rhythms and daily VIP administration entrained bioluminescence rhythms of astrocytes to a predicted phase angle. This is the first demonstration that a neuropeptide can entrain glial cells to a phase predicted by a phase response curve. We conclude that VIP potently entrains astrocytes in vitro and is a candidate for coordinating daily rhythms among glia in the brain. PMID:19346450

  3. Volumetric properties of human islet amyloid polypeptide in liquid water.

    PubMed

    Brovchenko, I; Andrews, M N; Oleinikova, A

    2010-04-28

    The volumetric properties of human islet amyloid polypeptide (hIAPP) in water were studied in a wide temperature range by computer simulations. The intrinsic density rho(p) and the intrinsic thermal expansion coefficient alpha(p) of hIAPP were evaluated by taking into account the difference between the volumetric properties of hydration and bulk water. The density of hydration water rho(h) was found to decrease almost linearly with temperature upon heating and its thermal expansion coefficient was found to be notably higher than that of bulk water. The peptide surface exposed to water is more hydrophobic and its rho(h) is smaller in conformation with a larger number of intrapeptide hydrogen bonds. The two hIAPP peptides studied (with and without disulfide bridge) show negative alpha(p), which is close to zero at 250 K and decreases to approximately -1.5 x 10(-3) K(-1) upon heating to 450 K. The analysis of various structural properties of peptides shows a correlation between the intrinsic peptide volumes and the number of intrapeptide hydrogen bonds. The obtained negative values of alpha(p) can be attributed to the shrinkage of the inner voids of the peptides upon heating.

  4. Free radical scavenging abilities of polypeptide from Chlamys farreri

    NASA Astrophysics Data System (ADS)

    Han, Zhiwu; Chu, Xiao; Liu, Chengjuan; Wang, Yuejun; Mi, Sun; Wang, Chunbo

    2006-09-01

    We investigated the radical scavenging effect and antioxidation property of polypeptide extracted from Chlamys farreri (PCF) in vitro using chemiluminescence and electron spin resonance (ESR) methods. We examined the scavenging effects of PCF on superoxide anions (O{2/-}), hydroxyl radicals (OH·), peroxynitrite (ONOO-) and the inhibiting capacity of PCF on peroxidation of linoleic acid. Our experiment suggested that PCF could scavenge oxygen free radicals including superoxide anions (O{2/-}) (IC50=0.3 mg/ml), hydroxyl radicals (OH·) (IC50=0.2 μg/ml) generated from the reaction systems and effectively inhibit the oxidative activity of ONOO- (IC50=0.2 mg/ml). At 1.25 mg/ml of PCF, the inhibition ratio on lipid peroxidation of linoleic acid was 43%. The scavenging effect of PCF on O{2/-}, OH· and ONOO- free radicals were stronger than those of vitamin C but less on lipid peroxidation of linoleic acid. Thus PCF could scavenge free radicals and inhibit the peroxidation of linoleic acid in vitro. It is an antioxidant from marine products and potential for industrial production in future.

  5. Polypeptide multilayer self-assembly studied by ellipsometry.

    PubMed

    Craig, Marina; Holmberg, Krister; Le Ru, Eric; Etchegoin, Pablo

    2014-01-01

    A polypeptide nanofilm made by layer-by-layer (LbL) self-assembly was built on a surface that mimics nonwoven, a material commonly used in wound dressings. Poly-L-lysine (PLL) and poly-L-glutamic acid (PLGA) are the building blocks of the nanofilm, which is intended as an enzymatically degradable lid for release of bactericides to chronic wounds. Chronic wounds often carry infection originating from bacteria such as Staphylococcus aureus and a release system triggered by the degree of infection is of interest. The dry nanofilm was studied with ellipsometry. The thickness of the nanofilm was 60% less in its dry state than in its wet state. The measurements showed that a primer was not necessary to build a stable nanofilm, which is practically important in our case because a nondegradable primer is highly unwanted in a wound care dressing. Added V8 (glutamyl endopeptidase) enzymes only showed adsorption on the nanofilm at room temperature, indicating that the PLL/PLGA "lid" may remain intact until the dressing has been filled with wound exudate at the elevated temperature typical of that of the wound.

  6. Low-dose pancreatic polypeptide inhibits food intake in man.

    PubMed

    Jesudason, David R; Monteiro, Mariana P; McGowan, Barbara M C; Neary, Nicola M; Park, Adrian J; Philippou, Elena; Small, Caroline J; Frost, Gary S; Ghatei, Mohammad A; Bloom, Stephen R

    2007-03-01

    Pancreatic polypeptide (PP) is a gut hormone released from the pancreas in response to food ingestion and remains elevated for up to 6 h postprandially. Plasma levels are elevated in patients with pancreatic tumours. An intravenous infusion of PP has been reported to reduce food intake in man, suggesting that PP is a satiety hormone. We investigated whether a lower infusion rate of PP would induce significant alterations in energy intake. The study was randomised and double-blinded. Fourteen lean fasted volunteers (five men and nine women) received 90 min infusions of PP (5 pmol/kg per min) and saline on two separate days. The dose chosen was half that used in a previous human study which reported a decrease in appetite but at supra-physiological levels of PP. One hour after the end of the infusion, a buffet lunch was served and energy intake measured. PP infusion was associated with a significant 11 % reduction in energy intake compared with saline (2440 (se 200) v. 2730 (se 180) kJ; P<0 x 05). Preprandial hunger as assessed by a visual analogue score was decreased in the PP-treated group compared to saline. These effects were achieved with plasma levels of PP within the pathophysiological range of pancreatic tumours.

  7. Intense fusion neutron sources

    NASA Astrophysics Data System (ADS)

    Kuteev, B. V.; Goncharov, P. R.; Sergeev, V. Yu.; Khripunov, V. I.

    2010-04-01

    The review describes physical principles underlying efficient production of free neutrons, up-to-date possibilities and prospects of creating fission and fusion neutron sources with intensities of 1015-1021 neutrons/s, and schemes of production and application of neutrons in fusion-fission hybrid systems. The physical processes and parameters of high-temperature plasmas are considered at which optimal conditions for producing the largest number of fusion neutrons in systems with magnetic and inertial plasma confinement are achieved. The proposed plasma methods for neutron production are compared with other methods based on fusion reactions in nonplasma media, fission reactions, spallation, and muon catalysis. At present, intense neutron fluxes are mainly used in nanotechnology, biotechnology, material science, and military and fundamental research. In the near future (10-20 years), it will be possible to apply high-power neutron sources in fusion-fission hybrid systems for producing hydrogen, electric power, and technological heat, as well as for manufacturing synthetic nuclear fuel and closing the nuclear fuel cycle. Neutron sources with intensities approaching 1020 neutrons/s may radically change the structure of power industry and considerably influence the fundamental and applied science and innovation technologies. Along with utilizing the energy produced in fusion reactions, the achievement of such high neutron intensities may stimulate wide application of subcritical fast nuclear reactors controlled by neutron sources. Superpower neutron sources will allow one to solve many problems of neutron diagnostics, monitor nano-and biological objects, and carry out radiation testing and modification of volumetric properties of materials at the industrial level. Such sources will considerably (up to 100 times) improve the accuracy of neutron physics experiments and will provide a better understanding of the structure of matter, including that of the neutron itself.

  8. Atomic data for fusion

    SciTech Connect

    Hunter, H.T.; Kirkpatrick, M.I.; Alvarez, I.; Cisneros, C.; Phaneuf, R.A.; Barnett, C.F.

    1990-07-01

    This report provides a handbook of recommended cross-section and rate-coefficient data for inelastic collisions between hydrogen, helium and lithium atoms, molecules and ions, and encompasses more than 400 different reactions of primary interest in fusion research. Published experimental and theoretical data have been collected and evaluated, and the recommended data are presented in tabular, graphical and parametrized form. Processes include excitation and spectral line emission, charge exchange, ionization, stripping, dissociation and particle interchange reactions. The range of collision energies is appropriate to applications in fusion-energy research.

  9. Fusion welding process

    DOEpatents

    Thomas, Kenneth C.; Jones, Eric D.; McBride, Marvin A.

    1983-01-01

    A process for the fusion welding of nickel alloy steel members wherein a ferrite containing pellet is inserted into a cavity in one member and melted by a welding torch. The resulting weld nugget, a fusion of the nickel containing alloy from the members to be welded and the pellet, has a composition which is sufficiently low in nickel content such that ferrite phases occur within the weld nugget, resulting in improved weld properties. The steel alloys encompassed also include alloys containing carbon and manganese, considered nickel equivalents.

  10. Fusion for Space Propulsion

    NASA Technical Reports Server (NTRS)

    Thio, Y. C. Francis; Schmidt, George R.; Santarius, John F.; Turchi, Peter J.; Siemon, Richard E.; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    The need for fusion propulsion for interplanetary flights is discussed. For a propulsion system, there are three important system attributes: (1) The absolute amount of energy available, (2) the propellant exhaust velocity, and (3) the jet power per unit mass of the propulsion system (specific power). For efficient and affordable human exploration of the solar system, propellant exhaust velocity in excess of 100 km/s and specific power in excess of 10 kW/kg are required. Chemical combustion obviously cannot meet the requirement in propellant exhaust velocity. Nuclear fission processes typically result in producing energy in the form of heat that needs to be manipulated at temperatures limited by materials to about 2,800 K. Using the fission energy to heat a low atomic weight propellant produces propellant velocity of the order of 10 kinds. Alternatively the fission energy can be converted into electricity that is used to accelerate particles to high exhaust velocity. However, the necessary power conversion and conditioning equipment greatly increases the mass of the propulsion system. Fundamental considerations in waste heat rejection and power conditioning in a fission electric propulsion system place a limit on its jet specific power to the order of about 0.2 kW/kg. If fusion can be developed for propulsion, it appears to have the best of all worlds - it can provide the largest absolute amount of energy, the propellant exhaust velocity (> 100 km/s), and the high specific jet power (> 10 kW/kg). An intermediate step towards fusion propulsion might be a bimodal system in which a fission reactor is used to provide some of the energy to drive a fusion propulsion unit. There are similarities as well as differences between applying fusion to propulsion and to terrestrial electrical power generation. The similarities are the underlying plasma and fusion physics, the enabling component technologies, the computational and the diagnostics capabilities. These physics and

  11. Hepatitis B e antigen polypeptides isolated from sera of individuals infected with hepatitis B virus: comparison with HBeAg polypeptide derived from Dane particles.

    PubMed

    Takahashi, K; Imai, M; Gotanda, T; Sano, T; Oinuma, A; Mishiro, S; Miyakawa, Y; Mayumi, M

    1980-09-01

    Hepatitis B e antigen (HBeAg) occurs in the serum of individuals infected with hepatitis B virus both free and in association with IgG. Utilizing a succession of steps involving salt precipitation, affinity chromatography, ion-exchange chromatography and isoelectrofocusing, we isolated free and IgG-bound forms of HBeAg from the sera of infected individuals with an overall gain in specific activity of 3000-fold and 540-fold, respectively. Polypeptide profiles of purified HBeAg preparations were studied by SDS-polyacrylamide gel electrophoresis in the presence of 2-mercaptoethanol. Both free and IgG-bound preparations revealed polypeptides with mol. wt. of 15500 (P15.5) and 16 500 (P16.5), and HBeAg activity was detected corresponding to their positions. The HBeAg polypeptides (P15.5/16.5) derived from sera were physicochemically different from the two polypeptides with HBeAg activity (P19 and P45) liberated from Dane particle cores by the conventional method involving incubation with Nonidet P40 and 2-mercaptoethanol. However, when core particles were prepared in the presence of a proteolytic enzyme, in addition to Nonidet P40 and 2-mercaptoethanol, they gave rise to HBeAg polypeptides with mol. wt. of 31000 (P31) and 15 500. Furthermore, P31 split into P15.5 when heated at 100 degrees C for 2 min. On the basis of these results, P15.5 may be assumed to be the essential polypeptide bearing HBeAg activity in the serum and also in Dane particles.

  12. Multisensor data fusion algorithm development

    SciTech Connect

    Yocky, D.A.; Chadwick, M.D.; Goudy, S.P.; Johnson, D.K.

    1995-12-01

    This report presents a two-year LDRD research effort into multisensor data fusion. We approached the problem by addressing the available types of data, preprocessing that data, and developing fusion algorithms using that data. The report reflects these three distinct areas. First, the possible data sets for fusion are identified. Second, automated registration techniques for imagery data are analyzed. Third, two fusion techniques are presented. The first fusion algorithm is based on the two-dimensional discrete wavelet transform. Using test images, the wavelet algorithm is compared against intensity modulation and intensity-hue-saturation image fusion algorithms that are available in commercial software. The wavelet approach outperforms the other two fusion techniques by preserving spectral/spatial information more precisely. The wavelet fusion algorithm was also applied to Landsat Thematic Mapper and SPOT panchromatic imagery data. The second algorithm is based on a linear-regression technique. We analyzed the technique using the same Landsat and SPOT data.

  13. Workmanship standards for fusion welding

    NASA Technical Reports Server (NTRS)

    Phillips, M. D.

    1967-01-01

    Workmanship standards manual defines practices, that adhere to rigid codes and specifications, for fusion welding of component piping, assemblies, and systems. With written and pictorial presentations, it is part of the operating procedure for fusion welding.

  14. Isolation of proteins related to the Rh polypeptides from nonhuman erythrocytes.

    PubMed Central

    Saboori, A M; Denker, B M; Agre, P

    1989-01-01

    It is thought that the Rh antigens may be important in maintaining normal erythrocyte membrane integrity. Despite their name, Rh antigens are serologically present only on human erythrocytes. Rh structural polymorphisms are known to reside within a family of nonglycosylated Mr 32,000 integral membrane proteins that can be purified by hydroxylapatite chromatography. Mr 32,000 integral membrane proteins were purified similarly from erythrocyte membrane vesicles prepared from rhesus monkeys, cows, cats, and rats, but could not be purified from human Rhmod erythrocytes, a rare syndrome lacking Rh antigens. The purified Mr 32,000 polypeptides were labeled with 125I, digested with chymotrypsin, and found to be 30-60% identical to human Rh polypeptides when compared by two-dimensional iodopeptide mapping. The physiologic function of the Rh polypeptides remains to be identified; however, the existence of related proteins in nonhuman erythrocytes supports the concept that the Rh polypeptides are erythrocyte membrane components of fundamental significance. Images PMID:2492035

  15. Characterization of the Large Picornaviral Polypeptides Produced in the Presence of Zinc Ion

    PubMed Central

    Butterworth, Byron E.; Korant, Bruce D.

    1974-01-01

    Zinc ion inhibits the posttranslational cleavages of human rhinovirus-1A, encephalomyocarditis virus, and poliovirus polypeptides. Each virus displayed a different susceptibility to zinc. However, in each case the cleavages of the capsid precursor and the cleavages analogous to the C → D → E conversion in encephalomyocarditis virus were most sensitive to zinc. Higher concentrations of zinc resulted in the buildup of even larger precursor polypeptides of a size between 106,000 and 214,000 daltons. The sizes of these polypeptides and the relative position of their gene loci on the viral RNA were determined. These data were used to place these polypeptides in the over-all scheme of viral protein processing. PMID:4367904

  16. Neutralizing determinants defined by monoclonal antibodies on polypeptides specified by bovine herpesvirus 1.

    PubMed Central

    Collins, J K; Butcher, A C; Riegel, C A; McGrane, V; Blair, C D; Teramoto, Y A; Winston, S

    1984-01-01

    Monoclonal antibodies were used to study neutralizing determinants on polypeptides of bovine herpesvirus 1. Two of three monoclonal antibodies which recognized nonoverlapping epitopes on a glycoprotein of 82,000 daltons were found to neutralize. A second group of monoclonal antibodies that individually precipitated five viral glycopolypeptides ranging in size from 102,000 to 55,000 daltons also neutralized. Two monoclonal antibodies which were the most efficient in neutralization recognized a non-glycosylated protein of 115,000 daltons which was the major polypeptide on the virus. A fourth group of monoclonal antibodies precipitated a non-glycosylated polypeptide of 91,000 daltons and several smaller polypeptides, but these antibodies demonstrated only limited neutralizing activity. Images PMID:6208375

  17. Theoretical investigations on model ternary polypeptides using genetic algorithm—Some new results

    NASA Astrophysics Data System (ADS)

    Arora, Vinita; Bakhshi, A. K.

    2011-04-01

    Using genetic algorithm (GA) model ternary polypeptides containing glycine, alanine and serine in β-pleated conformation have been theoretically investigated. In designing, the criterion to attain the optimum solution at the end of GA run is minimum band gap and maximum delocalization in the polypeptide chain. Ab initio results obtained using Clementi's minimal basis set are used as input. Effects of (i) change of basis set from minimal to double zeta, (ii) change in secondary structure from β-pleated to α-helical, (iii) presence of solvation shell and (iv) binding of H + and Li + ions to peptide group on the resulting solution as well as on electronic structure and conduction properties of polypeptides are investigated. A comparison is drawn between results obtained for the two cationic adducts. The protonated adduct is expected to withdraw more negative charge from the polypeptide chain due to smaller size of H + and is found to have high electron affinity compared to Li + adduct.

  18. Biosynthesis of metal-binding polypeptides and their precursors in response to cadmium in Datura innoxia

    SciTech Connect

    Jackson, P.J.; Delhaize, E.; Kuske, C.R.

    1991-01-01

    Metal-tolerant Datura innoxia cells synthesize large amounts of a class of metal-binding polypeptides, poly({gamma}-glutamylcysteinyl) glycines (({gamma}-EC){sub n}G, n=2-5), when exposed to Cd. These polypeptides have a high affinity for Cd (2) and certain other metal ions and are thought to play a role in metal tolerance in higher plants. ({gamma}-EC){sub n}G is biosynthetically derived from glutathione. Therefore, the response of Datura cells to Cd must include an increase in production of glutathione and its precursors, since cells rapidly accumulate very high concentrations of these metal-binding polypeptides. The biosynthesis of ({gamma}-EC){sub n}Gs, glutathione, and cysteine in response to Cd exposure is described. The physiological significance of the synthesis of these polypeptides and their precursors and its relevance to Cd tolerance and metal homeostasis are discussed. 34 refs., 6 figs., 1 tab.

  19. Polypeptide synthesis in columnar and squamous explants of human uterine cervix.

    PubMed

    Cowan, M E; Ward, K; Woodman, C B; Skinner, G R

    1982-10-01

    There were quantitative and qualitative differences in the in-vitro synthesis of 3 polypeptides between squamous and columnar epithelial explants of human cervix. One cross-linked keratin-like polypeptide of mol. wt 50,000 was synthesized and phosphorylated by squamous but not by columnar explants; a second cross-linked keratin-like polypeptide of mol. wt 52,000, which was present in larger amounts in squamous than columnar explants, was both glycosylated and phosphorylated during in-vitro explantation of squamous tissue; a third polypeptide of mol. wt 25,200 which was keratin-like but not cross-linked, was synthesized in squamous-tissue explants but in only 4% of columnar-tissue explants.

  20. Polypeptide synthesis in columnar and squamous explants of human uterine cervix.

    PubMed Central

    Cowan, M. E.; Ward, K.; Woodman, C. B.; Skinner, G. R.

    1982-01-01

    There were quantitative and qualitative differences in the in-vitro synthesis of 3 polypeptides between squamous and columnar epithelial explants of human cervix. One cross-linked keratin-like polypeptide of mol. wt 50,000 was synthesized and phosphorylated by squamous but not by columnar explants; a second cross-linked keratin-like polypeptide of mol. wt 52,000, which was present in larger amounts in squamous than columnar explants, was both glycosylated and phosphorylated during in-vitro explantation of squamous tissue; a third polypeptide of mol. wt 25,200 which was keratin-like but not cross-linked, was synthesized in squamous-tissue explants but in only 4% of columnar-tissue explants. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:6184064

  1. Pericarp polypeptides and SRAP markers associated with fruit quality traits in an interspecific tomato backcross.

    PubMed

    Pereira da Costa, J H; Rodríguez, G R; Pratta, G R; Picardi, L A; Zorzoli, R

    2014-01-24

    The aim of this study was to detect polypeptides and genomic regions associated with fruit quality traits in a backcross generation using as parent the Argentinean cultivated tomato Caimanta of Solanum lycopersicum and the wild accession LA722 of S. pimpinellifolium. We tested two types of molecular marker: polypeptide profile (at two ripening stages, mature green and red ripe) and SRAP (sequence-related amplified polymorphism). A polypeptide of 45 kDa present in the wild parents at the mature green stage was associated with larger fruit and long shelf life. Some amplification fragments from SRAP markers were associated with more than one quality trait such as fruit color, firmness, titratable acidity, and fruit soluble solids content. This study demonstrated for the first time the usefulness of the polypeptide profiles of pericarp and SRAP markers in finding associations with quality fruit traits in a tomato backcross generation.

  2. Fusion Engineering Device design description

    SciTech Connect

    Flanagan, C.A.; Steiner, D.; Smith, G.E.

    1981-12-01

    The US Magnetic Fusion Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. During 1981, the Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), developed a baseline design for the FED. This design is summarized herein.

  3. Fusion engineering device design description

    SciTech Connect

    Flanagan, C.A.; Steiner, D.; Smith, G.E.

    1981-12-01

    The US Magnetic Fusion Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. During 1981, the Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), developed a baseline design for the FED. This design is summarized herein.

  4. EXPRESSED PROTEIN LIGATION. A NEW TOOL FOR THE BIOSYNTHESIS OF CYCLIC POLYPEPTIDES

    SciTech Connect

    Kimura, R; Camarero, J A

    2004-11-11

    The present paper reviews the use of expressed protein ligation for the biosynthesis of backbone cyclic polypeptides. This general method allows the in vivo and in vitro biosynthesis of cyclic polypeptides using recombinant DNA expression techniques. Biosynthetic access to backbone cyclic peptides opens the possibility to generate cell-based combinatorial libraries that can be screened inside living cells for their ability to attenuate or inhibit cellular processes.

  5. Vasoactive Intestinal Polypeptide and Muscarinic Receptors: Supersensitivity Induced by Long-Term Atropine Treatment

    NASA Astrophysics Data System (ADS)

    Hedlund, Britta; Abens, Janis; Bartfai, Tamas

    1983-04-01

    Long-term treatment of rats with atropine induced large increases in the numbers of muscarinic receptors and receptors for vasoactive intestinal polypeptide in the salivary glands. Since receptors for vasoactive intestinal polypeptide coexist with muscarinic receptors on the same neurons in this preparation, the results suggest that a drug that alters the sensitivity of one receptor may also affect the sensitivity of the receptor for a costored transmitter and in this way contribute to the therapeutic or side effects of the drug.

  6. Identification and characterization of salt-inducible polypeptide in Paenibacillus sp., a moderately halophilic bacterium.

    PubMed

    Sokhansanj, Ashrafaddin; Karkhane, Ali Asghar; Jazii, Ferdous Rastgar

    2005-11-01

    In response to salt, Paenibacillus sp. strain XII expresses a 21.4 kDa polypeptide. N-terminal sequencing and sequence homology analysis indicate homology between the N-terminal sequence of the polypeptide and a segment of the N-terminus of the spore coat associated protein CotN of Oceanobacillus iheyensis, an extremely halotolerant bacteria of the deep-sea.

  7. Mars manned fusion spaceship

    SciTech Connect

    Hedrick, J.; Buchholtz, B.; Ward, P.; Freuh, J.; Jensen, E.

    1991-01-01

    Fusion Propulsion has an enormous potential for space exploration in the near future. In the twenty-first century, a usable and efficient fusion rocket will be developed and in use. Because of the great distance between other planets and Earth, efficient use of time, fuel, and payload is essential. A nuclear spaceship would provide greater fuel efficiency, less travel time, and a larger payload. Extended missions would give more time for research, experiments, and data acquisition. With the extended mission time, a need for an artificial environment exists. The topics of magnetic fusion propulsion, living modules, artificial gravity, mass distribution, space connection, and orbital transfer to Mars are discussed. The propulsion system is a magnetic fusion reactor based on a tandem mirror design. This allows a faster, shorter trip time and a large thrust to weight ratio. The fuel proposed is a mixture of deuterium and helium. Helium can be obtained from lunar mining. There will be minimal external radiation from the reactor resulting in a safe, efficient propulsion system.

  8. Mars manned fusion spaceship

    NASA Technical Reports Server (NTRS)

    Hedrick, James; Buchholtz, Brent; Ward, Paul; Freuh, Jim; Jensen, Eric

    1991-01-01

    Fusion Propulsion has an enormous potential for space exploration in the near future. In the twenty-first century, a usable and efficient fusion rocket will be developed and in use. Because of the great distance between other planets and Earth, efficient use of time, fuel, and payload is essential. A nuclear spaceship would provide greater fuel efficiency, less travel time, and a larger payload. Extended missions would give more time for research, experiments, and data acquisition. With the extended mission time, a need for an artificial environment exists. The topics of magnetic fusion propulsion, living modules, artificial gravity, mass distribution, space connection, and orbital transfer to Mars are discussed. The propulsion system is a magnetic fusion reactor based on a tandem mirror design. This allows a faster, shorter trip time and a large thrust to weight ratio. The fuel proposed is a mixture of deuterium and helium-3. Helium-3 can be obtained from lunar mining. There will be minimal external radiation from the reactor resulting in a safe, efficient propulsion system.

  9. Auditory Fusion in Children.

    ERIC Educational Resources Information Center

    Davis, Sylvia M.; McCroskey, Robert L.

    1980-01-01

    Focuses on auditory fusion (defined in terms of a listerner's ability to distinguish paired acoustic events from single acoustic events) in 3- to 12-year-old children. The subjects listened to 270 pairs of tones controlled for frequency, intensity, and duration. (CM)

  10. A fusion of minds

    NASA Astrophysics Data System (ADS)

    Corfield, Richard

    2013-02-01

    Mystery still surrounds the visit of the astronomer Sir Bernard Lovell to the Soviet Union in 1963. But his collaboration - and that of other British scientists - eased geopolitical tensions at the height of the Cold War and paved the way for today's global ITER fusion project, as Richard Corfield explains.

  11. Synergetic Multisensor Fusion

    DTIC Science & Technology

    1990-11-30

    technology have led to increased interest in using DEMs for navigation and other applications. In particular, DEMs are attractive for use in aircraft...Multisensor Fusion for Computer Vision [67]. 30 6. POSI!IONAL zSTIM&TION TECEnIQUzs FOR AN OUTDOOR MOBLE ROBOT The autonomous navigation of mobile robots is

  12. Fusion reactor materials

    SciTech Connect

    none,

    1989-01-01

    This paper discuses the following topics on fusion reactor materials: irradiation, facilities, test matrices, and experimental methods; dosimetry, damage parameters, and activation calculations; materials engineering and design requirements; fundamental mechanical behavior; radiation effects; development of structural alloys; solid breeding materials; and ceramics.

  13. [Fusion proteins encoded by orf 129L of ectromelia and orf A30L of smallpox viruses cross-react with neutralizing monoclonal antibodies].

    PubMed

    razumov, I A; Gileva, I P; Vasil'eva, M A; Nepomniashchikh, T S; Mishina, M N; Belanov, E F; Kochneva, G V; Konovalov, E E; Shchelkunov, S N; Loktev, V B

    2005-01-01

    Open reading frame (orf) 129L of ectromelia (EV) and orf A30L of smallpox viruses (SPV) encoding fusion proteins were cloned and expressed in E. coli cells. The recombinant polypeptides (prA30L H pr129L) were purified from cell lysates by Ni-NTA chromatography. Recombinant polypeptides were able to form trimers in buffered saline and they destroyed under treatment with SDS and 2-mercaptoethanol. Reactivity of prA30L, pr129L and orthopoxvirus proteins was analyzed by ELISA and Western blotting with panel of 22 monoclonal antibodies (MAbs) against orthopoxviruses (19 against EV, 2 MAbs against vaccinia virus and 1 Mabs against cowpox virus). This data allowed us to conclude that there are 12 EV-specific epitopes of pr129L and EV fusion proteins, ten orthopox-specific epitopes of EV, VV, CPV fusion proteins, from them 9 orthopox-specific epitopes of prA30L and SPV fusion proteins. Five Mabs, which cross-reacted with orthopox-specific epitopes, were able to neutralize the VV on Vero cells and from them two MAbs has neutralizing activity against smallpox virus. Our findings demonstrate that 129L fusion protein have EV-specific epitopes, that EV 129L and SPV A30L fusion proteins have a several orthopox-specific epitopes to induce a neutralizing antibodies against human pathogenic orthopoxviruses.

  14. Human-Centered Fusion Framework

    SciTech Connect

    Posse, Christian; White, Amanda M.; Beagley, Nathaniel

    2007-05-16

    In recent years the benefits of fusing signatures extracted from large amounts of distributed and/or heterogeneous data sources have been largely documented in various problems ranging from biological protein function prediction to cyberspace monitoring. In spite of significant progress in information fusion research, there is still no formal theoretical framework for defining various types of information fusion systems, defining and analyzing relations among such types, and designing information fusion systems using a formal method approach. Consequently, fusion systems are often poorly understood, are less than optimal, and/or do not suit user needs. To start addressing these issues, we outline a formal humancentered fusion framework for reasoning about fusion strategies. Our approach relies on a new taxonomy for fusion strategies, an alternative definition of information fusion in terms of parameterized paths in signature related spaces, an algorithmic formalization of fusion strategies and a library of numeric and dynamic visual tools measuring the impact as well as the impact behavior of fusion strategies. Using a real case of intelligence analysis we demonstrate that the proposed framework enables end users to rapidly 1) develop and implement alternative fusion strategies, 2) understand the impact of each strategy, 3) compare the various strategies, and 4) perform the above steps without having to know the mathematical foundations of the framework. We also demonstrate that the human impact on a fusion system is critical in the sense that small changes in strategies do not necessarily correspond to small changes in results.

  15. Graphite for fusion energy applications

    SciTech Connect

    Eatherly, W.P.; Clausing, R.E.; Strehlow, R.A.; Kennedy, C.R.; Mioduszewski, P.K.

    1987-03-01

    Graphite is in widespread and beneficial use in present fusion energy devices. This report reflects the view of graphite materials scientists on using graphite in fusion devices. Graphite properties are discussed with emphasis on application to fusion reactors. This report is intended to be introductory and descriptive and is not intended to serve as a definitive information source. (JDH)

  16. Synthesis of Tacaribe virus polypeptides in an in vitro coupled transcription and translation system.

    PubMed

    Boersma, D P; Compans, R W

    1985-04-01

    We have analyzed polypeptides synthesized in a coupled in vitro transcription and translation system in response to detergent-disrupted Tacaribe virus. Analysis of the major Tacaribe virus-specified product by two-dimensional polyacrylamide gel electrophoresis indicated that it had an isoelectric point similar to that of the Tacaribe nucleocapsid polypeptide N; however, the in vitro product had an approximate mol. wt. of 73 000, compared to a mol. wt. of 68 000 for the N protein. The 73 000 dalton product was found to yield proteolytic cleavage products with similar electrophoretic mobilities to those obtained from the virion P and N proteins. These results, as well as pulse-chase experiments in Tacaribe virus-infected cells, suggest that a 73 000 dalton polypeptide may be processed to yield the N polypeptide. The polypeptides synthesized in the coupled system depended on the amount and type of virus added; addition of purified Shark River (SR) virus, a member of the Patois group of bunyaviruses, resulted in synthesis of a polypeptide of mol. wt. 22 000 which corresponds to the SR nucleocapsid protein.

  17. Polypeptide composition of urea- and heat-resistant mutants of poliovirus types 1 and 2.

    PubMed

    Fennell, R; Phillips, B A

    1974-10-01

    Five urea-resistant and two heat-resistant mutants of poliovirus types 1 and 2 were isolated and their structural and nonstructural polypeptides compared to those of their wild-type, parental strains in an attempt to correlate mutant phenotypes with alterations in specific capsid polypeptides. Four of the seven mutants were found to contain polypeptides which differed in molecular weight from their respective parental viruses. However, resistance of virions to heat- or urea-inactivation could not be attributed to changes in particular capsid polypeptides because alterations were detected in all but one of the capsid components. For two of the urea-resistant mutants and one heat-resistant mutant, no differences were found in the molecular weights of the capsid and noncapsid polypeptides. These results, and the fact that at least 12 selective treatments were required to obtain stable mutants, indicate that: (i) such phenotypes probably can be expressed by mutations affecting one or more of the larger capsid polypeptides, and (ii) such phenotypes reflect multiple mutational steps.

  18. Proline-rich polypeptides in Alzheimer's disease and neurodegenerative disorders -- therapeutic potential or a mirage?

    PubMed

    Gladkevich, A; Bosker, F; Korf, J; Yenkoyan, K; Vahradyan, H; Aghajanov, M

    2007-10-01

    The development of effective and safe drugs for a growing Alzheimer disease population is an increasing need at present. Both experimental and clinical evidence support a beneficial effect of proline-rich polypeptides in a number of neurodegenerative diseases, including Alzheimer disease. Experimental data have shown that proline-rich polypeptides isolated from bovine neurohypophisis possess neuroprotective and neuromodulatory properties in mice with aluminum neurotoxicosis or neuronal damage caused by venoms and toxins. Proline-rich polypeptides from ovine colostrums, so called Colostrinin, have been shown to produce cognitive improvement in an experimental model and in patients with Alzheimer disease. However, the precise mechanism underlying the neuroprotective action of proline-rich polypeptides is not very well established. Moreover, studies pointing at a neuroprotective effect of proline-rich polypeptides from bovine neurohypophisis in humans have not been reported thus far. The authors conclude that more detailed information on the mode of action of proline-rich polypeptides is needed as well as confirmation of their efficacy in broad clinical trials before this approach can really show its potential in the treatment of neurodegenerative disorders.

  19. Collagen and keratin polypeptide models for assessing the natural and artificial protein decay of organic materials.

    PubMed

    Fotou, Evmorfia; Sakarellos-Daitsiotis, Maria; Ioakeimoglou, Eleni; Tziamourani, Eleni; Malea, Ekaterini; Panayiaris, George; Panou-Pomonis, Eugenia

    2016-11-01

    Among the materials constituting the natural and cultural heritage, organic materials of proteinaceous origin as bone (collagen), parchment and woolen textiles (keratin) are the most susceptible to damage and decay because of their exposure to air pollution, inappropriate values of ambient temperature, humidity and light. Aiming at contributing to the development of a reliable and reproducible immunoassay for the evaluation of collagen and keratin decay, three polypeptide models of these proteins were designed, synthesized and studied. Polypeptide [Pro-Ser(OBzl)-Gly]n incorporates the typical motif Pro-X-Gly of collagen; polypeptide [Pro-Cys(Acm)-Gly]n is a model of the C-terminal domain of type I keratin, corresponding to the repeating unit Pro-Cys-X of keratin, while polypeptide Ac-YRSGGGFGYRSGGGFGYRS-βAla-NH2 encloses the characteristic repeating sequence GGGFGYRS of the N-terminal part of Type II keratin. These polypeptides may be considered as simplified models that mimic fragments of collagen and keratin resulting from artificial and natural ageing or decay. It is concluded that high recognition of anti-polypeptide antibodies, produced after immunizations, by the bone, parchment and textile samples is indicative of high deterioration, while high anti-collagen or anti-keratin recognition is indicative of low deterioration. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  20. Polypeptide Point Modifications with Fatty Acid and Amphiphilic Block Copolymers for Enhanced Brain Delivery

    PubMed Central

    Batrakova, Elena V.; Vinogradov, Serguei V.; Robinson, Sandra M.; Niehoff, Michael L.; Banks, William A.; Kabanov, Alexander V.

    2009-01-01

    There is a tremendous need to enhance delivery of therapeutic polypeptides to the brain to treat disorders of the central nervous system (CNS). The brain delivery of many polypeptides is severely restricted by the blood—brain barrier (BBB). The present study demonstrates that point modifications of a BBB-impermeable polypeptide, horseradish peroxidase (HRP), with lipophilic (stearoyl) or amphiphilic (Pluronic block copolymer) moieties considerably enhance the transport of this polypeptide across the BBB and accumulation of the polypeptide in the brain in vitro and in vivo. The enzymatic activity of the HRP was preserved after the transport. The modifications of the HRP with amphiphilic block copolymer moieties through degradable disulfide links resulted in the most effective transport of the HRP across in vitro brain microvessel endothelial cell monolayers and efficient delivery of HRP to the brain. Stearoyl modification of HRP improved its penetration by about 60% but also increased the clearance from blood. Pluronic modification using increased penetration of the BBB and had no significant effect on clearance so that uptake by brain was almost doubled. These results show that point modification can improve delivery of even highly impermeable polypeptides to the brain. PMID:16029020

  1. Characterization of Mixed Polypeptide Colloidal Particles by Light Scattering

    NASA Astrophysics Data System (ADS)

    Shuman, Hannah E.; Gaeckle, Grace K.; Gavin, John; Holland, Nolan B.; Streletzky, Kiril A.

    2014-03-01

    Temperature-dependent polymer surfactants have been developed by connecting three elastin-like polypeptide (ELP) chains to a charged protein domain (foldon), forming a three-armed star polymer. At low temperatures the polymer is soluble, while at higher temperatures it forms micelles. The behavior of mixtures of the three-armed star ELP (E20-Foldon) and H40-Linear ELP chains was analyzed under different salt and protein concentrations and various foldon to linear ELP ratio using Depolarized Dynamic Light Scattering. It was expected that under certain conditions the pure E20-Foldon would form spherical micelles, which upon adding the linear ELP would change in size and possibly shape. The pure E20-Foldon indeed formed largely spherical micelles with Rh of 10-20nm in solutions with 15-100mM salt and protein concentration between 10 μM and 100 μM. For the mixtures of 50 μM E20-Foldon and varying concentrations of H40-Linear in 25mM of salt, it was discovered that low and high H40-Linear concentration (4 μM and 50 μM) had only one transition. For the mixtures with of 10 and 25 μM of H40-Linear the two distinct transition temperatures were observed by spectrophotometry. The first transition corresponded to significantly elongated diffusive particles of apparent Rh of 30-50nm, while the second transition corresponded to slightly anisotropic diffusive particles with apparent Rh of about 20nm. At all H40-Linear concentrations studied, diffusive particles were seen above the second transition. Their radius and ability to depolarize light increased with the increase of H40-Linear concentration.

  2. Islet Amyloid Polypeptide Membrane Interactions: Effects of Membrane Composition.

    PubMed

    Zhang, Xiaoxue; St Clair, Johnna R; London, Erwin; Raleigh, Daniel P

    2017-01-17

    Amyloid formation by islet amyloid polypeptide (IAPP) contributes to β-cell dysfunction in type 2 diabetes. Perturbation of the β-cell membrane may contribute to IAPP-induced toxicity. We examine the effects of lipid composition, salt, and buffer on IAPP amyloid formation and on the ability of IAPP to induce leakage of model membranes. Even low levels of anionic lipids promote amyloid formation and membrane permeabilization. Increasing the percentage of the anionic lipids, 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-l-serine (POPS) or 1,2-dioleoyl-sn-glycero-3-phospho(1'-rac-glycerol), enhances the rate of amyloid formation and increases the level of membrane permeabilization. The choice of zwitterionic lipid has no noticeable effect on membrane-catalyzed amyloid formation but in most cases affects leakage, which tends to decrease in the following order: 1,2-dioleoyl-sn-glycero-3-phosphocholine > 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine > sphingomyelin. Uncharged lipids that increase the level of membrane order weaken the ability of IAPP to induce leakage. Leakage is due predominately to pore formation rather than complete disruption of the vesicles under the conditions used in these studies. Cholesterol at or below physiological levels significantly reduces the rate of vesicle-catalyzed IAPP amyloid formation and decreases the susceptibility to IAPP-induced leakage. The effects of cholesterol on amyloid formation are masked by 25 mol % POPS. Overall, there is a strong inverse correlation between the time to form amyloid and the extent of vesicle leakage. NaCl reduces the rate of membrane-catalyzed amyloid formation by anionic vesicles, but accelerates amyloid formation in solution. The implications for IAPP membrane interactions are discussed, as is the possibility that the loss of phosphatidylserine asymmetry enhances IAPP amyloid formation and membrane damage in vivo via a positive feedback loop.

  3. Accelerators for heavy ion fusion

    SciTech Connect

    Bangerter, R.O.

    1985-10-01

    Large fusion devices will almost certainly produce net energy. However, a successful commercial fusion energy system must also satisfy important engineering and economic constraints. Inertial confinement fusion power plants driven by multi-stage, heavy-ion accelerators appear capable of meeting these constraints. The reasons behind this promising outlook for heavy-ion fusion are given in this report. This report is based on the transcript of a talk presented at the Symposium on Lasers and Particle Beams for Fusion and Strategic Defense at the University of Rochester on April 17-19, 1985.

  4. Surgical fusion in childhood spondylolisthesis.

    PubMed

    Stanton, R P; Meehan, P; Lovell, W W

    1985-01-01

    Twenty cases of surgical fusion for spondylolisthesis were reviewed at the Scottish Rite Hospital (Atlanta, GA, U.S.A.) to determine whether a procedure other than a simple posterolateral fusion is necessary for most patients. The patients were treated postoperatively with pantaloon spica cast immobilization. The fusion rate was high (90%), and patient satisfaction was high. One patient developed neurologic loss postoperatively. Two patients' slips progressed greater than 10% before solid fusion occurred. Thus, bilateral posterolateral fusion, followed by pantaloon spica cast immobilization, is effective for patients with symptomatic spondylolisthesis or asymptomatic children with grade 3 or greater slips. Reduction was not performed in this series.

  5. The path to fusion power.

    PubMed

    Llewellyn Smith, Chris; Ward, David

    2007-04-15

    Fusion is potentially an environmentally responsible and intrinsically safe source of essentially limitless power. It should be possible to build viable fusion power stations, and it looks as if the cost of fusion power will be reasonable. But time is needed to further develop the technology and to test in power station conditions the materials that would be used in their construction. Assuming no major adverse surprises, an orderly fusion development programme could lead to a prototype fusion power station putting electricity into the grid within 30 years, with commercial fusion power following some 10 or more years later. In the second half of the century, fusion could therefore be an important part of the portfolio of measures that are needed to cope with rising demand for energy in an environmentally responsible manner. In this paper, we describe the basics of fusion, its potential attractions, the status of fusion R&D, the remaining challenges and how they will be tackled at the International Tokamak Experimental Reactor and the proposed International Fusion Materials Irradiation Facility, and the timetable for the subsequent commercialization of fusion power.

  6. Construction of a Fusion Enzyme Exhibiting Superoxide Dismutase and Peroxidase Activity.

    PubMed

    Sharapov, M G; Novoselov, V I; Ravin, V K

    2016-04-01

    A chimeric gene construct encoding human peroxiredoxin 6 and Mn-superoxide dismutase from Escherichia coli was developed. Conditions for expression of the fusion protein in E. coli cell were optimized. Fusing of the enzymes into a single polypeptide chain with peroxiredoxin 6 at the N-terminus (PSH) did not affect their activities. On the contrary, the chimeric protein with reverse order of enzymes (SPH) was not obtained in a water-soluble active form. The active chimeric protein (PSH) exhibiting both peroxidase and superoxide dismutase activities was prepared and its physicochemical properties were characterized.

  7. The Need for Fusion Propulsion

    NASA Technical Reports Server (NTRS)

    Cassibry, Jason

    2005-01-01

    Fusion propulsion is inevitable if the human race remains dedicated to exploration of the solar system. There are fundamental reasons why fusion surpasses more traditional approaches to routine crewed missions to Mars, crewed missions to the outer planets, and deep space high speed robotic missions, assuming that reduced trip times, increased payloads, and higher available power are desired. A recent series of informal discussions were held among members from government, academia, and industry concerning fusion propulsion. We compiled a sufficient set of arguments for utilizing fusion in space. If the U.S. is to lead the effort and produce a working system in a reasonable amount of time, NASA must take the initiative, relying on, but not waiting for, DOE guidance. In this talk those arguments for fusion propulsion are presented, along with fusion enabled mission examples, fusion technology trade space, and a proposed outline for future efforts.

  8. Evaluation of a UCMK/dCK fusion enzyme for gemcitabine-mediated cytotoxicity

    SciTech Connect

    Johnson, Adam J.; Brown, Melissa N.; Black, Margaret E.

    2011-12-09

    Highlights: Black-Right-Pointing-Pointer Goal was to enhance dFdC cytotoxicity by the creation of a UCMK/dCK fusion enzyme. Black-Right-Pointing-Pointer The UCMK/dCK fusion enzyme possesses both native activities. Black-Right-Pointing-Pointer The fusion renders cells equally sensitive to dFdC relative to dCK expression alone. Black-Right-Pointing-Pointer Dual activities of fusion not sufficient to augment cell dFdC sensitivity in vitro. Black-Right-Pointing-Pointer Data may warrant the implementation of UCMK mutagenesis studies. -- Abstract: While gemcitabine (2 Prime -2 Prime -difluoro-2 Prime -deoxycytidine, dFdC) displays wide-ranging antineoplastic activity as a single agent, variable response rates and poor intracellular metabolism often limit its clinical efficacy. In an effort to enhance dFdC cytotoxicity and help normalize response rates, we created a bifunctional fusion enzyme that combines the enzymatic activities of deoxycytidine kinase (dCK) and uridine/cytidine monophosphate kinase (UCMK) in a single polypeptide. Our goal was to evaluate whether the created fusion could induce beneficial, functional changes toward dFdC, expedite dFdC conversion to its active antimetabolites and consequently amplify cell dFdC sensitivity. While kinetic analyses revealed the UCMK/dCK fusion enzyme to possess both native activities, the fusion rendered cells sensitive to the cytotoxic effects of dFdC at the same level as dCK expression alone. These results suggest that increased wild-type UCMK expression does not provide a significant enhancement in dFdC-mediated cytotoxicity and may warrant the implementation of studies aimed at engineering UCMK variants with improved activity toward gemcitabine monophosphate.

  9. Fusion Data Grid Service

    NASA Astrophysics Data System (ADS)

    Shasharina, Svetlana; Wang, Nanbor

    2004-11-01

    Simulations and experiments in the fusion and plasma physics community generate large datasets at remote sites. Visualization and analysis of these datasets are difficult because of the incompatibility among the various data formats adopted by simulation, experiments, and analysis tools, and the large sizes of analyzed data. Grids and Web Services technologies are capable of providing solutions for such heterogeneous settings, but need to be customized to the field-specific needs and merged with distributed technologies currently used by the community. This paper describes how we are addressing these issues in the Fusion Grid Service under development. We also present performance results of relevant data transfer mechanisms including binary SOAP, DIME, GridFTP and MDSplus and CORBA. We will describe the status of data converters (between HDF5 and MDSplus data types), developed in collaboration with MIT (J. Stillerman). Finally, we will analyze bottlenecks of MDSplus data transfer mechanism (work performed in collaboration with General Atomics (D. Schissel and M. Qian).

  10. Experiments in cold fusion

    SciTech Connect

    Palmer, E.P.

    1986-03-28

    The work of Steve Jones and others in muon-catalyzed cold fusion of deuterium and hydrogen suggests the possibility of such fusion catalyzed by ions, or combinations of atoms, or more-or-less free electrons in solid and liquid materials. A hint that this might occur naturally comes from the heat generated in volcanic action in subduction zones on the earth. It is questionable whether the potential energy of material raised to the height of a midocean ridge and falling to the depth of an ocean trench can produce the geothermal effects seen in the volcanoes of subduction zones. If the ridge, the trench, the plates, and the asthenosphere are merely visible effects of deeper density-gradient driven circulations, it is still uncertain that observed energy-concentration effects fit the models.

  11. Fusion pumped laser

    DOEpatents

    Pappas, D.S.

    1987-07-31

    The apparatus of this invention may comprise a system for generating laser radiation from a high-energy neutron source. The neutron source is a tokamak fusion reactor generating a long pulse of high-energy neutrons and having a temperature and magnetic field effective to generate a neutron flux of at least 10/sup 15/ neutrons/cm/sup 2//center dot/s. Conversion means are provided adjacent the fusion reactor at a location operable for converting the high-energy neutrons to an energy source with an intensity and energy effective to excite a preselected lasing medium. A lasing medium is spaced about and responsive to the energy source to generate a population inversion effective to support laser oscillations for generating output radiation. 2 figs., 2 tabs.

  12. Unconventional approaches to fusion

    SciTech Connect

    Brunelli, B.; Leotta, G.G.

    1982-01-01

    This volume is dedicated to unconventional approaches to fusionthose thermonuclear reactors that, in comparison with Tokamak and other main lines, have received little attention in the worldwide scientific community. Many of the approaches considered are still in the embryonic stages. The authors-an international group of active nuclear scientists and engineers-focus on the parameters achieved in the use of these reactors and on the meaning of the most recent physical studies and their implications for the future. They also compare these approaches with conventional ones, the Tokamak in particular, stressing the non-plasma-physics requirements of fusion reactors. Unconventional compact toroids, linear systems, and multipoles are considered, as are the ''almost conventional'' fusion machines: stellarators, mirrors, reversed-field pinches, and EBT.

  13. Maximum Likelihood Fusion Model

    DTIC Science & Technology

    2014-08-09

    data fusion, hypothesis testing,maximum likelihood estimation, mobile robot navigation REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT...61 vi 9 Bibliography 62 vii 10 LIST OF FIGURES 1.1 Illustration of mobile robotic agents. Land rovers such as (left) Pioneer robots ...simultaneous localization and mapping 1 15 Figure 1.1: Illustration of mobile robotic agents. Land rovers such as (left) Pioneer robots , (center) Segways

  14. Fusion development and technology

    SciTech Connect

    Montgomery, D.B.

    1992-01-01

    This report discusses the following: superconducting magnet technology; high field superconductors; advanced magnetic system and divertor development; poloidal field coils; gyrotron development; commercial reactor studies--aries; ITER physics: alpha physics and alcator R D for ITER; lower hybrid current drive and heating in the ITER device; ITER superconducting PF scenario and magnet analysis; ITER systems studies; and safety, environmental and economic factors in fusion development.

  15. (Fusion energy research)

    SciTech Connect

    Phillips, C.A.

    1988-01-01

    This report discusses the following topics: principal parameters achieved in experimental devices (FY88); tokamak fusion test reactor; Princeton beta Experiment-Modification; S-1 Spheromak; current drive experiment; x-ray laser studies; spacecraft glow experiment; plasma deposition and etching of thin films; theoretical plasma; tokamak modeling; compact ignition tokamak; international thermonuclear experimental reactor; Engineering Department; Project Planning and Safety Office; quality assurance and reliability; and technology transfer.

  16. Modular Aneutronic Fusion Engine

    SciTech Connect

    Gary Pajer, Yosef Razin, Michael Paluszek, A.H. Glasser and Samuel Cohen

    2012-05-11

    NASA's JUNO mission will arrive at Jupiter in July 2016, after nearly five years in space. Since operational costs tend to rise with mission time, minimizing such times becomes a top priority. We present the conceptual design for a 10MW aneutronic fusion engine with high exhaust velocities that would reduce transit time for a Jupiter mission to eighteen months and enable more challenging exploration missions in the solar system and beyond. __________________________________________________

  17. Isolation of two polypeptides comprising the neutrophil-immobilizing factor of human leucocytes.

    PubMed Central

    Watt, K W; Brightman, I L; Goetzl, E J

    1983-01-01

    Human leucocyte lysosomal polypeptides of mol. wt 4000-5000, which constitute the neutrophil-immobolizing factor (NIF), were isolated from the 22,000 g supernate of sonicates of human neutrophils by filtration on Sephadex G-75. The larger (NIF-1) and smaller (NIF-2) of the polypeptides were resolved by filtration on Bio-Gel P6 and purified to homogeneity by sequential reverse-phase high performance liquid chromatography and paper electrophoresis. The results of analyses of amino acid composition indicated that NIF-1 and NIF-2 are distinct polypeptides composed of an apparent total of 41 and 38 amino acids, respectively. Both NIF polypeptides contain one cysteine and one methionine, lack isoleucine, tyrosine and phenylalanine, and are rich in histidine and proline. The sequence of 20 of the amino-terminal amino acids of both NIF polypeptides is identical, but NIF-2 possesses an additional alanine at the amino-terminus. Highly purified NIF-1 and NIF-2 inhibited human neutrophil random migration and chemotaxis to diverse stimuli in a concentration-dependent manner, with 50% inhibition of chemotaxis by 0.31-1 x 10(-8) M NIF-1 and 1-3 x 10(-7) M NIF-2. Neither NIF polypeptide was cytotoxic for neutrophils, altered neutrophil phagocytosis or release of lysosomal enzymes, or inhibited mononuclear leucocyte chemotaxis. The leucocyte and functional specificity of the NIF polypeptides and the quantitites released upon stimulation of the human leucocytes suggest that the transition to a mononuclear leucocyte population in chronic inflammation may be attributable in part to the NIF derived from the leucocyte infiltrates of acute responses. PMID:6848456

  18. Biochemical and biophysical characterization of the transmissible gastroenteritis coronavirus fusion core

    SciTech Connect

    Ma Guangpeng; Feng Youjun; Gao Feng; Wang Jinzi; Liu Cheng; Li Yijing . E-mail: yijingli@163.com

    2005-12-02

    Transmissible gastroenteritis coronavirus (TGEV) is one of the most destructive agents, responsible for the enteric infections that are lethal for suckling piglets, causing enormous economic loss to the porcine fostering industry every year. Although it has been known that TGEV spiker protein is essential for the viral entry for many years, the detail knowledge of the TGEV fusion protein core is still very limited. Here, we report that TGEV fusion core (HR1-SGGRGG-HR2), in vitro expressed in GST prokaryotic expression system, shares the typical properties of the trimer of coiled-coil heterodimer (six {alpha}-helix bundle), which has been confirmed by a combined series of biochemical and biophysical evidences including size exclusion chromatography (gel-filtration), chemical crossing, and circular diagram. The 3D homologous structure model presents its most likely structure, extremely similar to those of the coronaviruses documented. Taken together, TGEV spiker protein belongs to the class I fusion protein, characterized by the existence of two heptad-repeat (HR) regions, HR1 and HR2, and the present knowledge about the truncated TGEV fusion protein core may facilitate in the design of the small molecule or polypeptide drugs targeting the membrane fusion between TGEV and its host.

  19. Cold fusion studies

    NASA Astrophysics Data System (ADS)

    Hembree, D. M.; Burchfield, L. A.; Fuller, E. L., Jr.; Perey, F. G.; Mamantov, G.

    1990-06-01

    A series of experiments designed to detect the by-products expected from deuterium fusion occurring in the palladium and titanium cathodes of heavy water, D2O, electrolysis cells is reported. The primary purpose of this account is to outline the integrated experimental design developed to test the cold fusion hypothesis and to report preliminary results that support continuing the investigation. Apparent positive indicators of deuterium fusion were observed, but could not be repeated or proved to originate from the electrochemical cells. In one instance, two large increases in the neutron count rate, the largest of which exceeded the background by 27 standard deviations, were observed. In a separate experiment, one of the calorimetry cells appeared to be producing approximately 18 percent more power that the input value, but thermistor failure prevented an accurate recording of the event as a function of time. In general, the tritium levels in most cells followed the slow enrichment expected from the electrolysis of D2O containing a small amount of tritium. However, after 576 hours of electrolysis, one cell developed a tritium concentration approximately seven times greater than expected level.

  20. Stabilized Spheromak Fusion Reactors

    SciTech Connect

    Fowler, T

    2007-04-03

    The U.S. fusion energy program is focused on research with the potential for studying plasmas at thermonuclear temperatures, currently epitomized by the tokamak-based International Thermonuclear Experimental Reactor (ITER) but also continuing exploratory work on other plasma confinement concepts. Among the latter is the spheromak pursued on the SSPX facility at LLNL. Experiments in SSPX using electrostatic current drive by coaxial guns have now demonstrated stable spheromaks with good heat confinement, if the plasma is maintained near a Taylor state, but the anticipated high current amplification by gun injection has not yet been achieved. In future experiments and reactors, creating and maintaining a stable spheromak configuration at high magnetic field strength may require auxiliary current drive using neutral beams or RF power. Here we show that neutral beam current drive soon to be explored on SSPX could yield a compact spheromak reactor with current drive efficiency comparable to that of steady state tokamaks. Thus, while more will be learned about electrostatic current drive in coming months, results already achieved in SSPX could point to a productive parallel development path pursuing auxiliary current drive, consistent with plans to install neutral beams on SSPX in the near future. Among possible outcomes, spheromak research could also yield pulsed fusion reactors at lower capital cost than any fusion concept yet proposed.

  1. Effect of sequence on the ionization behavior of a series of amphiphilic polypeptides.

    PubMed

    Fowler, Michael; Siddique, Bushra; Duhamel, Jean

    2013-04-09

    The behavior of five polypeptides made of hydrophilic and pH-responsive aspartic acid (Asp) and hydrophobic phenylalanine (Phe), which had been prepared by stitching together short well-defined sequences of Asp and Phe, was studied as a function of pH. The effect of pH on these polypeptides referred to as (Asp3Phe1)n, (Asp2Phe1)n, (Asp1Phe1)n, (Asp1Phe2)n, and (Asp1Phe3)n varied dramatically depending on their constituting sequence. The more hydrophobic polypeptides (Asp1Phe2)n and (Asp1Phe3)n behaved as if the Asp's were isolated from each other and showed an apparent pKa (pKa(app)) that remained constant with level of ionization (α = [Asp(-)]/[Asp]total) and equaled 5.4 and 6.4, respectively. The more hydrophilic polypeptides (Asp3Phe1)n and (Asp2Phe1)n behaved like weak polyacids showing a linear increase in pKa(app) with increasing α. The pKa(app) of (Asp1Phe1)n showed a trend as a function of α intermediate between the Asp-rich and Phe-rich polypeptides, behaving as if the Asp's were isolated at low α values (<0.35) but acting as a weak polyacid for large α values (>0.35). The effect that α, and thus the charge density of the polypeptides, had on the collapse and aggregation of the polypeptides was characterized by conducting static light scattering and fluorescence measurements. Static light scattering measurements demonstrated that all polypeptides precipitated and aggregated in solution at a critical charge density of 0.2. Fluorescence measurements with pyrene indicated that this behavior was due to the formation of Phe aggregates in water. Together, these experiments provide a complete description of how pH affects the behavior of a series of unique amphiphilic polypeptides designed with a well-defined sequence.

  2. Oligosaccharyltransferase Subunits Bind Polypeptide Substrate to Locally Enhance N-glycosylation*

    PubMed Central

    Jamaluddin, M. Fairuz B.; Bailey, Ulla-Maja; Schulz, Benjamin L.

    2014-01-01

    Oligosaccharyltransferase is a multiprotein complex that catalyzes asparagine-linked glycosylation of diverse proteins. Using yeast genetics and glycoproteomics, we found that transient interactions between nascent polypeptide and Ost3p/Ost6p, homologous subunits of oligosaccharyltransferase, were able to modulate glycosylation efficiency in a site-specific manner in vivo. These interactions were driven by hydrophobic and electrostatic complementarity between amino acids in the peptide-binding groove of Ost3p/Ost6p and the sequestered stretch of substrate polypeptide. Based on this dependence, we used in vivo scanning mutagenesis and in vitro biochemistry to map the precise interactions that affect site-specific glycosylation efficiency. We conclude that transient binding of substrate polypeptide by Ost3p/Ost6p increases glycosylation efficiency at asparagines proximal and C-terminal to sequestered sequences. We detail a novel mode of interaction between translocating nascent polypeptide and oligosaccharyltransferase in which binding to Ost3p/Ost6p segregates a short flexible loop of glycosylation-competent polypeptide substrate that is delivered to the oligosaccharyltransferase active site for efficient modification. PMID:25118247

  3. Polypeptide multilayer film co-delivers oppositely-charged drug molecules in sustained manners.

    PubMed

    Jiang, Bingbing; Defusco, Elizabeth; Li, Bingyun

    2010-12-13

    The current state-of-the-art for drug-carrying biomedical devices is mostly limited to those that release a single drug. Yet there are many situations in which more than one therapeutic agent is needed. Also, most polyelectrolyte multilayer films intended for drug delivery are loaded with active molecules only during multilayer film preparation. In this paper, we present the integration of capsules as vehicles within polypeptide multilayer films for sustained release of multiple oppositely charged drug molecules using layer-by-layer nanoassembly technology. Calcium carbonate (CaCO(3)) particles were impregnated with polyelectrolytes, shelled with polyelectrolyte multilayers, and then assembled onto polypeptide multilayer films using glutaraldehyde. Capsule-integrated polypeptide multilayer films were obtained after decomposition of CaCO(3) templates. Two oppositely charged drugs were loaded into capsules within polypeptide multilayer films postpreparation based on electrostatic interactions between the drugs and the polyelectrolytes impregnated within capsules. We determined that the developed innovative capsule-integrated polypeptide multilayer films could be used to load multiple drugs of very different properties (e.g., opposite charges) any time postpreparation (e.g., minutes before surgical implantation inside an operating room), and such capsule-integrated films allowed simultaneous delivery of two oppositely charged drug molecules and a sustained (up to two weeks or longer) and sequential release was achieved.

  4. Synthesis of a major integral membrane polypeptide of rat liver peroxisomes on free polysomes.

    PubMed Central

    Fujiki, Y; Rachubinski, R A; Lazarow, P B

    1984-01-01

    The manner of synthesis and assembly of the peroxisomal membrane proteins is unknown. Understanding these processes is essential to an understanding of the formation of the organelle. We have investigated the biogenesis of the previously identified major 21.7-kDa integral peroxisomal membrane polypeptide [Fujiki, Y., Fowler, S., Shio, H., Hubbard, A. L. & Lazarow, P. B. (1982) J. Cell Biol. 93, 103-110]. This protein was purified to apparent homogeneity and used to elicit a rabbit antiserum. In immunoblotting analysis, antibody bound only to the 22-kDa membrane polypeptide present exclusively in peroxisomal membranes. Total rat liver RNA was translated in a nuclease-treated rabbit reticulocyte cell-free protein-synthesizing system. The in vitro translation product, isolated by means of the antibody and Staphylococcus aureus cells, comigrated with the mature 22-kDa polypeptide in NaDodSO4/PAGE. Analysis of the translation products of RNAs from free and membrane-bound polysomes indicated that the mRNA for the 22-kDa membrane polypeptide is found predominantly in free polysomes. The results imply post-translational insertion of the membrane polypeptide into the peroxisomal membrane without proteolytic processing and suggest that peroxisomes, like mitochondria and chloroplasts, form by fission from preexisting organelles. Images PMID:6594687

  5. Congenital deficiency of two polypeptide subunits of the iron-protein fragment of mitochondrial complex I.

    PubMed

    Moreadith, R W; Cleeter, M W; Ragan, C I; Batshaw, M L; Lehninger, A L

    1987-02-01

    Recently, we described a patient with severe lactic acidosis due to congenital complex I (NADH-ubiquinone oxidoreductase) deficiency. We now report further enzymatic and immunological characterizations. Both NADH and ferricyanide titrations of complex I activity (measured as NADH-ferricyanide reductase) were distinctly altered in the mitochondria from the patient's tissues. In addition, antisera against complex I immunoprecipitated NADH-ferricyanide reductase from the control but not the patient's mitochondria. However, immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of complex I polypeptides demonstrated that the majority of the 25 polypeptides comprising complex I were present in the affected mitochondria. A more detailed analysis using subunit selective antisera against the main polypeptides of the iron-protein fragments of complex I revealed a selective absence of the 75- and 13-kD polypeptides. These findings suggest that the underlying basis for this patient's disease was a congenital deficiency of at least two polypeptides comprising the iron-protein fragment of complex I, which resulted in the inability to correctly assemble a functional enzyme complex.

  6. Export is the default pathway for soluble unfolded polypeptides that accumulate during expression in Escherichia coli

    SciTech Connect

    Scotto-Lavino, E.; Freimuth, P.; Bai, M.; Zhang, Y.-B.

    2011-09-01

    Several E. coli endogenous, cytoplasmic proteins that are known clients of the chaperonin GroEL were overexpressed to examine the fate of accumulated unfolded polypeptides. Substantial fractions of about half of the proteins formed insoluble aggregates, consistent with the hypothesis that these proteins were produced at rates or in amounts that exceeded the protein-folding capacity of GroEL. In addition, large fractions of three overexpressed GroEL client proteins were localized in an extra-cytoplasmic, osmotically-sensitive compartment, suggesting they had initially accumulated in the cytoplasm as soluble unfolded polypeptides and thus were able to access a protein export pathway. Consistent with this model, an intrinsically unfoldable, hydrophilic, non-secretory polypeptide was quantitatively exported from the E. coli cytoplasm into an osmotically-sensitive compartment. Our results support the conclusion that a soluble, unfolded conformation alone may be sufficient to direct non-secretory polypeptides into a protein export pathway for signal peptide-independent translocation across the inner membrane, and that export rather than degradation by cytoplasmic proteases is the preferred fate for newly-synthesized, soluble, unfolded polypeptides that accumulate in the cytoplasm. The stable folded conformation of exported GroEL client proteins further suggests that the requirement for GroEL may be conditional on protein folding in the molecularly-crowded environment of the cytoplasm.

  7. Inheritance behavior of information coding for small subunit polypeptides of fraction 1 protein.

    PubMed

    Chen, K; Wildman, S G

    1980-12-01

    In various genera of plants, the small subunit of fraction 1 protein is often composed of more than one kind of polypeptide; these differ in isoelectric points and amino acid composition. Previous analysis of numerous individual progeny of Nicotiana tabacum (two kinds of polypeptides), N. glauca + N. langsdorffii parasexual hybrids (three kinds) and other examples showed no change in F-1 protein composition as a consequence of alternation of generations. Experiments reported here show that absence of one number of each of the 24 different pairs of chromosomes in an N. tabacum monosomic series and also absence of the "S" pair in a nullisome did not affect F-1 protein composition. Absence of the "E" pair caused reduction in the amount of the least acidic of the two kinds of N. tabacum small subunit polypeptides. The question of how many individual progeny of self-fertile hybrids would have to be analyzed to detect segregation of genes coding for F-1 protein small subunit polypeptides, if segregation occurs, was answered by analysis of F1 hybrids between N. otophora and N. tomentosiformis, and two subspecies of N. suaveolens, together with their F2 progeny. In both cases, analysis of 16 progeny was sufficient to demonstrate a segregation pattern of two F1 hybrid type to one each of the two parental types. Therefore, in the absence of segregation, it is likely that coding information for different kinds of F-1 protein small subunit polypeptides is sequestered on heterologous chromosomes, as postulated in previous reports.

  8. DVL, a novel class of small polypeptides: overexpression alters Arabidopsis development.

    PubMed

    Wen, Jiangqi; Lease, Kevin A; Walker, John C

    2004-03-01

    Small polypeptides can act as important regulatory molecules that coordinate cellular responses required for differentiation, growth, and development. In a gain-of-function genetic screen for genes that influence fruit development in Arabidopsis, we identified a novel gene -DEVIL1 (DVL1) - encoding a small protein. Overexpression of DVL1 results in pleiotropic phenotypes featured by shortened stature, rounder rosette leaves, clustered inflorescences, shortened pedicles, and siliques with pronged tips. cDNA analysis indicates that DVL1 has a 153-nucleotide (nt) open-reading frame (ORF) encoding a 51-amino acid polypeptide that shares no significant similarity to previously identified proteins. Sequence alignment shows that DVL1 belongs to a family of related genes that are limited to angiosperm plants. Ectopic overexpression of each of the five closely related Arabidopsis DVL genes causes similar phenotypic changes, suggesting overlapping function in the DVL gene family. Point mutations of conserved amino acids in the C-terminal region of the DVL1 polypeptide reveal that these conserved residues are required for DVL1-overexpression phenotypes. Our results show that the DVL family is a novel class of small polypeptides and the overexpression phenotypes suggest that these polypeptides may have a role in plant development.

  9. Application of Statistical Thermodynamics To Predict the Adsorption Properties of Polypeptides in Reversed-Phase HPLC.

    PubMed

    Tarasova, Irina A; Goloborodko, Anton A; Perlova, Tatyana Y; Pridatchenko, Marina L; Gorshkov, Alexander V; Evreinov, Victor V; Ivanov, Alexander R; Gorshkov, Mikhail V

    2015-07-07

    The theory of critical chromatography for biomacromolecules (BioLCCC) describes polypeptide retention in reversed-phase HPLC using the basic principles of statistical thermodynamics. However, whether this theory correctly depicts a variety of empirical observations and laws introduced for peptide chromatography over the last decades remains to be determined. In this study, by comparing theoretical results with experimental data, we demonstrate that the BioLCCC: (1) fits the empirical dependence of the polypeptide retention on the amino acid sequence length with R(2) > 0.99 and allows in silico determination of the linear regression coefficients of the log-length correction in the additive model for arbitrary sequences and lengths and (2) predicts the distribution coefficients of polypeptides with an accuracy from 0.98 to 0.99 R(2). The latter enables direct calculation of the retention factors for given solvent compositions and modeling of the migration dynamics of polypeptides separated under isocratic or gradient conditions. The obtained results demonstrate that the suggested theory correctly relates the main aspects of polypeptide separation in reversed-phase HPLC.

  10. Exposure of salivary gland cells to low-frequency electromagnetic fields alters polypeptide synthesis.

    PubMed Central

    Goodman, R; Henderson, A S

    1988-01-01

    This study demonstrates that exposure of cells to extremely low-frequency electromagnetic fields can cause measurable changes in protein synthesis. Sciara coprophila salivary gland cells were exposed to five low-frequency (1.5-72 Hz) electromagnetic signals: three signals (1.5, 15, and 72 Hz) produced pulsed asymmetric electromagnetic fields and two signals (60 and 72 Hz) were sinusoidal. Subsequent analyses of two-dimensional gels showed that cell exposure to either type of low-frequency electromagnetic field resulted in both qualitative and quantitative changes in patterns of protein synthesis. Thus, signals producing diverse waveform characteristics induced previously undetectable polypeptides, some of which were signal specific and augmented or suppressed other polypeptides as compared with nonexposed cells. The pattern of polypeptide synthesis differed from that seen with heat shock: only five polypeptides in cells exposed to electromagnetic signals overlap those polypeptides exposed to heat shock, and the suppression of protein synthesis characteristic of heat shock does not occur. Images PMID:3375247

  11. Competition between surface adsorption and folding of fibril-forming polypeptides

    NASA Astrophysics Data System (ADS)

    Ni, Ran; Kleijn, J. Mieke; Abeln, Sanne; Cohen Stuart, Martien A.; Bolhuis, Peter G.

    2015-02-01

    Self-assembly of polypeptides into fibrillar structures can be initiated by planar surfaces that interact favorably with certain residues. Using a coarse-grained model, we systematically studied the folding and adsorption behavior of a β -roll forming polypeptide. We find that there are two different folding pathways depending on the temperature: (i) at low temperature, the polypeptide folds in solution into a β -roll before adsorbing onto the attractive surface; (ii) at higher temperature, the polypeptide first adsorbs in a disordered state and folds while on the surface. The folding temperature increases with increasing attraction as the folded β -roll is stabilized by the surface. Surprisingly, further increasing the attraction lowers the folding temperature again, as strong attraction also stabilizes the adsorbed disordered state, which competes with folding of the polypeptide. Our results suggest that to enhance the folding, one should use a weakly attractive surface. They also explain the recent experimental observation of the nonmonotonic effect of charge on the fibril formation on an oppositely charged surface [C. Charbonneau et al., ACS Nano 8, 2328 (2014), 10.1021/nn405799t].

  12. [Image fusion in medical radiology].

    PubMed

    Burger, C

    1996-07-20

    Image fusion supports the correlation between images of two or more studies of the same organ. First, the effect of differing geometries during image acquisitions, such as a head tilt, is compensated for. As a consequence, congruent images can easily be obtained. Instead of merely putting them side by side in a static manner and burdening the radiologist with the whole correlation task, image fusion supports him with interactive visualization techniques. This is especially worthwhile for small lesions as they can be more precisely located. Image fusion is feasible today. Easy and robust techniques are readily available, and furthermore DICOM, a rapidly evolving data exchange standard, diminishes the once severe compatibility problems for image data originating from systems of different manufacturers. However, the current solutions for image fusion are not yet established enough for a high throughput of fusion studies. Thus, for the time being image fusion is most appropriately confined to clinical research studies.

  13. High Level Information Fusion (HLIF) with nested fusion loops

    NASA Astrophysics Data System (ADS)

    Woodley, Robert; Gosnell, Michael; Fischer, Amber

    2013-05-01

    Situation modeling and threat prediction require higher levels of data fusion in order to provide actionable information. Beyond the sensor data and sources the analyst has access to, the use of out-sourced and re-sourced data is becoming common. Through the years, some common frameworks have emerged for dealing with information fusion—perhaps the most ubiquitous being the JDL Data Fusion Group and their initial 4-level data fusion model. Since these initial developments, numerous models of information fusion have emerged, hoping to better capture the human-centric process of data analyses within a machine-centric framework. 21st Century Systems, Inc. has developed Fusion with Uncertainty Reasoning using Nested Assessment Characterizer Elements (FURNACE) to address challenges of high level information fusion and handle bias, ambiguity, and uncertainty (BAU) for Situation Modeling, Threat Modeling, and Threat Prediction. It combines JDL fusion levels with nested fusion loops and state-of-the-art data reasoning. Initial research has shown that FURNACE is able to reduce BAU and improve the fusion process by allowing high level information fusion (HLIF) to affect lower levels without the double counting of information or other biasing issues. The initial FURNACE project was focused on the underlying algorithms to produce a fusion system able to handle BAU and repurposed data in a cohesive manner. FURNACE supports analyst's efforts to develop situation models, threat models, and threat predictions to increase situational awareness of the battlespace. FURNACE will not only revolutionize the military intelligence realm, but also benefit the larger homeland defense, law enforcement, and business intelligence markets.

  14. Network-centric data fusion

    NASA Astrophysics Data System (ADS)

    Nicholson, David; Lloyd, C. M.; Collins, Peter R. C.

    2002-08-01

    The performance of three distributed sensor fusion network architectures is investigated: a fully-connected and a partially-connected measurement fusion system and a partially-connected track fusion system. The investigation employs an advanced military scenario generator, FLAMES, which was customised for exercising a range of distributed data fusion experiments. Specifically, it includes a representative model of the delays in a communication system (such as JTIDS or Link 16). Here the delays were used to modify communication bandwidth and to evaluate how this affected the performance of the fusion architectures/algorithms. Under certain specific scenario conditions, it was found that decentralised measurement fusion system was severely affected by reduced bandwidth. This is because each node loads its communication buffer with every measurement and consequently some measurements are never transmitted. The decentralised track fusion system exhibits improved performance because it lumps measurements into tracks and thereby it makes much more effective use of the bandwidth. Moreover, it was found that the performance of the partially connected decentralised track fusion system was very close to the optimal performance achieved by the fully-connected decentralised measurement fusion system.

  15. OCULUS Sea Track Fusion Service

    NASA Astrophysics Data System (ADS)

    Panagiotou, Stylianos C.; Rizogiannis, Constantinos; Katsoulis, Stavros; Lampropoulos, Vassilis; Kanellopoulos, Sotirios; Thomopoulos, Stelios C. A.

    2015-06-01

    Oculus Sea is a complete solution regarding maritime surveillance and communications at Local as well as Central Command and Control level. It includes a robust and independent track fusion service whose main functions include: 1) Interaction with the User to suggest the fusion of two or more tracks, confirm Track ID and Vessel Metadata creation for the fused track, and suggest de-association of two tracks 2) Fusion of same vessel tracks arriving simultaneously from multiple radar sensors featuring track Association, track Fusion of associated tracks to produce a more accurate track, and Multiple tracking filters and fusion algorithms 3) Unique Track ID Generator for each fused track 4) Track Dissemination Service. Oculus Sea Track Fusion Service adopts a system architecture where each sensor is associated with a Kalman estimator/tracker that obtains an estimate of the state vector and its respective error covariance matrix. Finally, at the fusion center, association and track state estimation fusion are carried out. The expected benefits of this system include multi-sensor information fusion, enhanced spatial resolution, and improved target detection.

  16. Economic potential of inertial fusion

    SciTech Connect

    Nuckolls, J.H.

    1984-04-01

    Beyond the achievement of scientific feasibility, the key question for fusion energy is: does it have the economic potential to be significantly cheaper than fission and coal energy. If fusion has this high economic potential then there are compelling commercial and geopolitical incentives to accelerate the pace of the fusion program in the near term, and to install a global fusion energy system in the long term. Without this high economic potential, fusion's success depends on the failure of all alternatives, and there is no real incentive to accelerate the program. If my conjectures on the economic potential of inertial fusion are approximately correct, then inertial fusion energy's ultimate costs may be only half to two-thirds those of advanced fission and coal energy systems. Relative cost escalation is not assumed and could increase this advantage. Both magnetic and inertial approaches to fusion potentially have a two-fold economic advantage which derives from two fundamental properties: negligible fuel costs and high quality energy which makes possible more efficient generation of electricity. The wining approach to fusion may excel in three areas: electrical generating efficiency, minimum material costs, and adaptability to manufacture in automated factories. The winning approach must also rate highly in environmental potential, safety, availability factor, lifetime, small 0 and M costs, and no possibility of utility-disabling accidents.

  17. Cold nuclear fusion

    NASA Astrophysics Data System (ADS)

    Tsyganov, E. N.; Bavizhev, M. D.; Buryakov, M. G.; Dabagov, S. B.; Golovatyuk, V. M.; Lobastov, S. P.

    2015-07-01

    If target deuterium atoms were implanted in a metal crystal in accelerator experiments, a sharp increase in the probability of DD-fusion reaction was clearly observed when compared with the reaction's theoretical value. The electronic screening potential, which for a collision of free deuterium atoms is about 27 eV, reached 300-700 eV in the case of the DD-fusion in metallic crystals. These data leads to the conclusion that a ban must exist for deuterium atoms to be in the ground state 1s in a niche filled with free conduction electrons. At the same time, the state 2p whose energy level is only 10 eV above that of state 1s is allowed in these conditions. With anisotropy of 2p, 3p or above orbitals, their spatial positions are strictly determined in the lattice coordinate system. When filling out the same potential niches with two deuterium atoms in the states 2p, 3p or higher, the nuclei of these atoms can be permanently positioned without creating much Coulomb repulsion at a very short distance from each other. In this case, the transparency of the potential barrier increases dramatically compared to the ground state 1s for these atoms. The probability of the deuterium nuclei penetrating the Coulomb barrier by zero quantum vibration of the DD-system also increases dramatically. The so-called cold nuclear DD-fusion for a number of years was registered in many experiments, however, was still rejected by mainstream science for allegedly having no consistent scientific explanation. Finally, it received the validation. Below, we outline the concept of this explanation and give the necessary calculations. This paper also considers the further destiny of the formed intermediate state of 4He∗.

  18. mim3 and nam3 omnipotent suppressor genes similarly affect the polypeptide composition of yeast mitoribosomes.

    PubMed

    Mieszczak, M; Zagórski, W

    1987-05-01

    Yeast informational suppressors of mit- mutations coded for by nuclear (nam3-1, nam3-2) or by mitochondrial DNA (mim3-1) affect the mitoribosome. Nuclear mutations result in the appearance of an additional polypeptide called SI in the small mitoribosomal subunit. An identical polypeptide, not detected in the wild type 37S subunit, is present in crude preparations of mitoribosomes isolated from a mim3-1 suppressor carrying strain. Traces of the SI polypeptide may be found in highly purified small subunits from the mim3-1 strain. Therefore, mutations affecting either mitochondrial rRNA (mim3-1) or mitochondrial r-proteins (nam3-1, nam3-2) could be followed by similar changes in overall mitoribosome structure. This may explain the functional similarity of nuclear and mitochondrially coded suppressors.

  19. Selective covalent bond formation in polypeptide ions via gas-phase ion/ion reaction chemistry.

    PubMed

    Han, Hongling; McLuckey, Scott A

    2009-09-16

    Primary amines present in protonated polypeptides can be covalently modified via gas-phase ion/ion reactions using bifunctional reagent ions. The use of reagent anions with a charge-bearing site that leads to strong interactions with the polypeptide, such as sulfonic acid, gives rise to the formation of a long-lived adduct. A distinct reactive functional group, an aldehyde in the present case, can then undergo reaction with the peptide. Collisional activation of the adduct ion formed from a reagent with an aldehyde group and a peptide ion with a primary amine gives rise to water loss in conjunction with imine (Schiff base) formation. The covalently bound modification is retained upon subsequent collisional activation. This work demonstrates the ability to selectively modify polypeptide ions in the gas phase within the context of a multistage mass spectrometry experiment.

  20. Structural characterization of reverse transcriptase and endonuclease polypeptides of the acquired immunodeficiency syndrome retrovirus.

    PubMed Central

    Lightfoote, M M; Coligan, J E; Folks, T M; Fauci, A S; Martin, M A; Venkatesan, S

    1986-01-01

    Automated N-terminal microsequencing of immune affinity-purified acquired immunodeficiency syndrome retrovirus polypeptides from infected cells was used to locate the N termini of 64-, 51-, and 34-kilodalton (kDa) polypeptides within the pol open reading frame (ORF) of the proviral DNA. The 64- and 51-kDa proteins had identical N termini (Pro-Ile-Ser-Pro-IIe-Glu-Thr-Val-) positioned 156 residues from the beginning of the pol ORF. The N terminus of the 34-kDa pol gene product, Phe-Leu-Asp-Gly-Ile-Asp-Lys-, mapped 716 residues into the pol ORF. These polypeptides were absent in an RT-negative, CD4-negative, persistently infected cell line (8E5) carrying a single defective copy of a constitutively expressed, integrated proviral DNA. Images PMID:2430111

  1. Magnetite loaded Polypeptide-PLGA multifunctional microbubbles for dual-mode US/MR imaging.

    PubMed

    Sun, Ying; Zhu, Yunkai; Huang, Can; Li, Rongxin; Chen, Yaqing; Duan, Yourong

    2016-01-01

    Magnetite loaded Polypeptide-PLGA multifunctional microbubbles (Fe3O4 /Polypeptide-PLGA MMBs) that show superparamagnetic properties were prepared by a modified double emulsion method and employed as imaging agent for dual-mode Ultrasound/Magnetic resonance (US/MR) imaging of prostatic cancer. The successful synthesis of MMBs was determined by Fourier Transform Infrared Spectrometer (FTIR), X-ray diffraction (XRD), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Atomic Absorption Spectroscopy (AAS) and vibrating sample magnetometer (VSM). The as-prepared MMBs had a diameter of 700 nm and were quite safe as confirmed by MTT assays. Prussian Blue Staining showed that targeted Fe3O4 /Polypeptide-PLGA MMBs enhanced the cellular uptake efficiency. In cell attachment study, adherence of MMBs was significantly higher to LNCaP cells compared with negative control PC3 cells. The in vitro results demonstrated that these MMBs could enhance both US and MR imaging of prostatic cancer.

  2. Involvement of Rh blood group polypeptides in the maintenance of aminophospholipid asymmetry

    SciTech Connect

    Schroit, A.J.; Connor, J. ); Bloy, C.; Carton, J-P. )

    1990-11-01

    The human erythrocyte (RBC) Rh blood group system consists of a complex of distinct integral membrane polypeptides with physical properties common to the aminophospholipid transporter responsible for the transbilayer movement of phosphatidylserine (PS) in RBC. To assess the involvement of Rh polypeptides in PS translocation, the aminophospholipid translocase was labeled with a photoactivatable PS analogue, {sup 125}I-azido-PS, and with an inhibitor of PS transport, {sup 125}I-labeled 2-(2-pyridyldithio)ethylamine. The ability of monoclonal Rh antibodies to immunoprecipitate the labeled transporter was determined. Immunoprecipitated Rh polypeptides were found to be labeled with the aminophospholipid translocase markers, suggesting that Rh proteins are involved in the transbilayer movement of PS.

  3. Comparison between the polypeptide profile of halophilic bacteria and salt tolerant plants.

    PubMed

    Muñoz, G; González, C; Flores, P; Prado, B; Campos, V

    1997-12-01

    Changes in the polypeptide profile induced by salt stress in halotolerant and halophilic bacteria, isolated from the Atacama desert (northern Chile), were compared with those in the cotyledons of Prosopis chilensis (Leguminoseae) seedlings, a salt tolerant plant. SDS-PAGE analyses show the presence of four predominant polypeptides, with molecular weights around 78, 70, 60 and 44 kDa respectively, both in bacteria and in cotyledons from P. chilensis seedlings raised under salt stress conditions. Moreover, the 60 and 44 kDa polypeptides seem to be salt responsive, since their concentration increases with increasing NaCl in the growth medium. Our results suggest a common mechanism for salt tolerance in prokaryotes and in eukaryotes.

  4. Structure-function relationship in the antifreeze activity of synthetic alanine-lysine antifreeze polypeptides.

    PubMed

    Wierzbicki, A; Knight, C A; Rutland, T J; Muccio, D D; Pybus, B S; Sikes, C S

    2000-01-01

    Recently antifreeze proteins (AFP) have been the subject of many structure-function relationship studies regarding their antifreeze activity. Attempts have been made to elucidate the structure-function relationship by various amino acid substitutions, but to our knowledge there has been no successful from first principles design of a polypeptide that would bind to designated ice planes along a specific direction. In this paper we show the results of our first attempt on an entirely de novo design of an alanine-lysine-rich antifreeze polypeptide. This 43 residue alanine-lysine peptide exhibits characteristic nonequilibrium freezing point depression and binds to the designated (210) planes of ice along the [122] vector. The structural and thermodynamic properties of this polypeptide were determined using circular dichroism spectroscopy and its nonequilibrium antifreeze properties were investigated using an ice-etching method and nanoliter osmometry.

  5. Physics of Fusion Welding

    NASA Technical Reports Server (NTRS)

    Nunes, A. C., Jr.

    1986-01-01

    Applicabilities and limitations of three techniques analyzed. NASA technical memorandum discusses physics of electron-beam, gas/ tungsten-arc, and laser-beam welding. From comparison of capabilities and limitations of each technique with regard to various welding conditions and materials, possible to develop criteria for selecting best welding technique in specific application. All three techniques classified as fusion welding; small volume of workpiece melted by intense heat source. Heat source moved along seam, leaving in wake solid metal that joins seam edges together.

  6. Cold Fusion Verification.

    DTIC Science & Technology

    1991-03-01

    published work, talking with others in the field, and attending conferences, that CNF probably is chimera and will go the way of N-rays and polywater ...way of N-rays and polywater . To date, no one, including Pons and Fleischmann, has been able to construct a so-called CNF electrochemical cell that...Cold Nuclear Fusion (CNF), as originally reported in 1989. The conclusion is that CNF probably is chimera and will go the way of N-rays and polywater

  7. Fusion reactor pumped laser

    DOEpatents

    Jassby, Daniel L.

    1988-01-01

    A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam.

  8. Medial septal and median raphe innervation of vasoactive intestinal polypeptide-containing interneurons in the hippocampus.

    PubMed

    Papp, E C; Hajos, N; Acsády, L; Freund, T F

    1999-05-01

    Vasoactive intestinal polypeptide-immunoreactive interneurons are known to form three anatomically and neurochemically well-characterized neuron populations in the hippocampus. Two of these establish synaptic contacts selectively with other GABAergic cells (interneuron-selective cells), whereas the third type innervates pyramidal cell bodies and proximal dendrites like a conventional basket cell. Our aim was to examine which of the vasoactive intestinal polypeptide-containing interneuron populations are among the targets of GABAergic septohippocampal and serotonergic raphe-hippocampal pathways. Anterograde tracing with Phaseolus vulgaris leucoagglutinin combined with double immunocytochemistry for vasoactive intestinal polypeptide was used at the light and electron microscopic levels. Our results show that both interneuron-selective cells and vasoactive intestinal polypeptide-containing basket cells receive synaptic input from the medial septum and median raphe nucleus. The GABAergic component of the septohippocampal pathway establishes multiple contacts on both cell types. In the case of the raphe-hippocampal projection, single or double contacts were more frequent on vasoactive intestinal polypeptide-positive interneuron selective cells (76%), whereas multiple contacts predominated on basket cells (83%). The extrinsic GABAergic innervation of interneuron-selective cells in the hippocampus indicates a complex interaction among GABAergic systems, which might ensure the timing and rhythmic synchronization of inhibitory processes in the hippocampus. On the other hand, our results suggest that the serotonergic effect on perisomatic inhibition is exerted via vasoactive intestinal polypeptide-containing basket cells that are functionally distinct from their parvalbumin-positive relatives, which appear to escape control of serotonergic as well as local interneuron-selective cells.

  9. Chlorophyll-Protein Complexes from Euglena gracilis and Mutants Deficient in Chlorophyll b: II. Polypeptide Composition.

    PubMed

    Cunningham, F X; Schiff, J A

    1986-01-01

    Chlorophyll-protein complexes (CPs) obtained from thylakoids of Euglena gracilis Klebs var bacillaris Cori contain the following polypeptides (listed in parentheses in order of prominence after Coomassie R-250 staining of polyacrylamide gels): CP Ia (66, 18, 22, 22.5, 27.5, 21, 28, 24, 25.5, and 26 kilodaltons [kD]); CP I (66 kD); CPx (41 kD); LHCP(2) (an oligomer of LHCP) (26.5, 28, and 26 kD); CPy (27 and 19 kD); CPa (54 kD); and LHCP (26.5, 28, and 26 kD). Mutants of bacillaris low in chlorophyll b (Gr(1)BSL, G(1)BU, and O(4)BSL; Chl a/b [mol/mol] = 50-100) which lack CP Ia, LHCP(2), and LHCP also lack or are deficient in polypeptides associated with these complexes in wild-type cells. Mutants G(1) and O(4), which also lack CPy, lack the CPy-associated polypeptides found in wild-type and Gr(1). Using an antiserum which was elicited by and reacts strongly and selectively with the SDS-treated major polypeptide (26.5 kD) of the LHCP complexes of wild-type, this polypeptide is undetectable in the mutants (<0.25% of the level in wild-type on a cell basis); the antiserum does not react with the SDS-treated 28 kD polypeptide of the Euglena LHCP complexes and cross-reacts only very weakly with components in SDS-treated cells of Chlamydomonas reinhardtii Dangeard and chloroplasts of Spinacia oleracea L. cv Winter Bloomsdale. Rates of photosynthesis of the wild-type and mutant cells of Euglena are approximately equal on a cell basis when measured at light saturation, consistent with the selective loss of major antenna components but not CP I or CPa from the mutants.

  10. Expression of a connexin 43/beta-galactosidase fusion protein inhibits gap junctional communication in NIH3T3 cells

    PubMed Central

    1995-01-01

    Gap junctions contain membrane channels that mediate the cell-to-cell movement of ions, metabolites and cell signaling molecules. As gap junctions are comprised of a hexameric array of connexin polypeptides, the expression of a mutant connexin polypeptide may exert a dominant negative effect on gap junctional communication. To examine this possibility, we constructed a connexin 43 (Cx43)/beta-galactosidase (beta-gal) expression vector in which the bacterial beta-gal protein is fused in frame to the carboxy terminus of Cx43. This vector was transfected into NIH3T3 cells, a cell line which is well coupled via gap junctions and expresses high levels of Cx43. Transfectant clones were shown to express the fusion protein by northern and western analysis. X-Gal staining further revealed that all of the fusion protein containing cells also expressed beta-gal enzymatic activity. Double immunostaining with a beta-gal and Cx43 antibody demonstrated that the fusion protein is immunolocalized to the perinuclear region of the cytoplasm and also as punctate spots at regions of cell-cell contact. This pattern is similar to that of Cx43 in the parental 3T3 cells, except that in the fusion protein expressing cells, Cx43 expression was reduced at regions of cell-cell contact. Examination of gap junctional communication (GJC) with dye injection studies further showed that dye coupling was inhibited in the fusion protein expressing cells, with the largest reduction in coupling found in a clone exhibiting little Cx43 localization at regions of cell-cell contact. When the fusion protein expression vector was transfected into the communication poor C6 cell line, abundant fusion protein expression was observed, but unlike the transfected NIH3T3 cells, no fusion protein was detected at the cell surface. Nevertheless, dye coupling was inhibited in these C6 cells. Based on these observations, we propose that the fusion protein may inhibit GJC by sequestering the Cx43 protein intracellularly

  11. Pancreatic vasoactive intestinal polypeptide-oma as a cause of secretory diarrhoea.

    PubMed

    Masel, S L; Brennan, B A; Turner, J H; Cullingford, G L; Cullen, D J

    2000-04-01

    A 42-year-old woman presented with a 4-year history of worsening diarrhoea that was watery, profuse and confirmed to be secretory in nature. She had tested positive for phenolphthalein on urinary laxative screening but continued to deny laxative usage. Her vasoactive intestinal polypeptide (VIP) level was subsequently found to be markedly elevated. Despite a normal abdominal ultrasound, a computed tomography scan revealed a 5-cm pancreatic tail mass. Octreotide scanning was used to exclude metastatic disease and she went on to have surgical removal of a localized pancreatic vasoactive intestinal polypeptide-oma which resulted in the complete resolution of her diarrhoea.

  12. Catalytic and reactive polypeptides and methods for their preparation and use

    DOEpatents

    Schultz, Peter

    1994-01-01

    Catalytic and reactive polypeptides include a binding site specific for a reactant or reactive intermediate involved in a chemical reaction of interest. The polypeptides further include at least one active functionality proximate the binding site, where the active functionality is capable of catalyzing or chemically participating in the chemical reaction in such a way that the reaction rate is enhanced. Methods for preparing the catalytic peptides include chemical synthesis, site-directed mutagenesis of antibody and enzyme genes, covalent attachment of the functionalities through particular amino acid side chains, and the like.

  13. Inertial confinement fusion

    SciTech Connect

    Powers, L.; Condouris, R.; Kotowski, M.; Murphy, P.W.

    1992-01-01

    This issue of the ICF Quarterly contains seven articles that describe recent progress in Lawrence Livermore National Laboratory's ICF program. The Department of Energy recently initiated an effort to design a 1--2 MJ glass laser, the proposed National Ignition Facility (NIF). These articles span various aspects of a program which is aimed at moving forward toward such a facility by continuing to use the Nova laser to gain understanding of NIF-relevant target physics, by developing concepts for an NIF laser driver, and by envisioning a variety of applications for larger ICF facilities. This report discusses research on the following topics: Stimulated Rotational Raman Scattering in Nitrogen; A Maxwell Equation Solver in LASNEX for the Simulation of Moderately Intense Ultrashort Pulse Experiments; Measurements of Radial Heat-Wave Propagation in Laser-Produced Plasmas; Laser-Seeded Modulation Growth on Directly Driven Foils; Stimulated Raman Scattering in Large-Aperture, High-Fluence Frequency-Conversion Crystals; Fission Product Hazard Reduction Using Inertial Fusion Energy; Use of Inertial Confinement Fusion for Nuclear Weapons Effects Simulations.

  14. Statistics in fusion experiments

    NASA Astrophysics Data System (ADS)

    McNeill, D. H.

    1997-11-01

    Since the reasons for the variability in data from plasma experiments are often unknown or uncontrollable, statistical methods must be applied. Reliable interpretation and public accountability require full data sets. Two examples of data misrepresentation at PPPL are analyzed: Te >100 eV on S-1 spheromak.(M. Yamada, Nucl. Fusion 25, 1327 (1985); reports to DoE; etc.) The reported high values (statistical artifacts of Thomson scattering measurements) were selected from a mass of data with an average of 40 eV or less. ``Correlated'' spectroscopic data were meaningless. (2) Extrapolation to Q >=0.5 for DT in TFTR.(D. Meade et al., IAEA Baltimore (1990), V. 1, p. 9; H. P. Furth, Statements to U. S. Congress (1989).) The DD yield used there was the highest through 1990 (>= 50% above average) and the DT to DD power ratio used was about twice any published value. Average DD yields and published yield ratios scale to Q<0.15 for DT, in accord with the observed performance over the last 3 1/2 years. Press reports of outlier data from TFTR have obscured the fact that the DT behavior follows from trivial scaling of the DD data. Good practice in future fusion research would have confidence intervals and other descriptive statistics accompanying reported numerical values (cf. JAMA).

  15. Helium Find Thaws the Cold Fusion Trail.

    ERIC Educational Resources Information Center

    Pennisi, E.

    1991-01-01

    Reported is a study of cold fusion in which trace amounts of helium, possible evidence of an actual fusion reaction, were found. Research methodology is detailed. The controversy over the validity of experimental results with cold fusion are reviewed. (CW)

  16. Fusion Power measurement at ITER

    SciTech Connect

    Bertalot, L.; Barnsley, R.; Krasilnikov, V.; Stott, P.; Suarez, A.; Vayakis, G.; Walsh, M.

    2015-07-01

    Nuclear fusion research aims to provide energy for the future in a sustainable way and the ITER project scope is to demonstrate the feasibility of nuclear fusion energy. ITER is a nuclear experimental reactor based on a large scale fusion plasma (tokamak type) device generating Deuterium - Tritium (DT) fusion reactions with emission of 14 MeV neutrons producing up to 700 MW fusion power. The measurement of fusion power, i.e. total neutron emissivity, will play an important role for achieving ITER goals, in particular the fusion gain factor Q related to the reactor performance. Particular attention is given also to the development of the neutron calibration strategy whose main scope is to achieve the required accuracy of 10% for the measurement of fusion power. Neutron Flux Monitors located in diagnostic ports and inside the vacuum vessel will measure ITER total neutron emissivity, expected to range from 1014 n/s in Deuterium - Deuterium (DD) plasmas up to almost 10{sup 21} n/s in DT plasmas. The neutron detection systems as well all other ITER diagnostics have to withstand high nuclear radiation and electromagnetic fields as well ultrahigh vacuum and thermal loads. (authors)

  17. Multi-sensor fusion development

    NASA Astrophysics Data System (ADS)

    Bish, Sheldon; Rohrer, Matthew; Scheffel, Peter; Bennett, Kelly

    2016-05-01

    The U.S. Army Research Laboratory (ARL) and McQ Inc. are developing a generic sensor fusion architecture that involves several diverse processes working in combination to create a dynamic task-oriented, real-time informational capability. Processes include sensor data collection, persistent and observational data storage, and multimodal and multisensor fusion that includes the flexibility to modify the fusion program rules for each mission. Such a fusion engine lends itself to a diverse set of sensing applications and architectures while using open-source software technologies. In this paper, we describe a fusion engine architecture that combines multimodal and multi-sensor fusion within an Open Standard for Unattended Sensors (OSUS) framework. The modular, plug-and-play architecture of OSUS allows future fusion plugin methodologies to have seamless integration into the fusion architecture at the conceptual and implementation level. Although beyond the scope of this paper, this architecture allows for data and information manipulation and filtering for an array of applications.

  18. Cellulose binding domain fusion proteins

    SciTech Connect

    Shoseyov, Oded; Shpiegl, Itai; Goldstein, Marc A.; Doi, Roy H.

    1998-01-01

    A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production thereof. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques.

  19. Cold fusion; Myth versus reality

    SciTech Connect

    Rabinowitz, M. )

    1990-01-01

    Experiments indicate that several different nuclear reactions are taking place. Some of the experiments point to D-D fusion with a cominant tritium channel as one of the reactions. The article notes a similarity between Prometheus and the discoveries of cold fusion.

  20. Fusion Policy Advisory Committee (FPAC)

    SciTech Connect

    Not Available

    1990-09-01

    This document is the final report of the Fusion Policy Advisory Committee. The report conveys the Committee's views on the matters specified by the Secretary in his charge and subsequent letters to the Committee, and also satisfies the provisions of Section 7 of the Magnetic Fusion Energy Engineering Act of 1980, Public Law 96-386, which require a triennial review of the conduct of the national Magnetic Fusion Energy program. Three sub-Committee's were established to address the large number of topics associated with fusion research and development. One considered magnetic fusion energy, a second considered inertial fusion energy, and the third considered issues common to both. For many reasons, the promise of nuclear fusion as a safe, environmentally benign, and affordable source of energy is bright. At the present state of knowledge, however, it is uncertain that this promise will become reality. Only a vigorous, well planned and well executed program of research and development will yield the needed information. The Committee recommends that the US commit to a plan that will resolve this critically important issue. It also outlines the first steps in a development process that will lead to a fusion Demonstration Power Plant by 2025. The recommended program is aggressive, but we believe the goal is reasonable and attainable. International collaboration at a significant level is an important element in the plan.

  1. Cold Fusion, A Journalistic Investigation

    NASA Astrophysics Data System (ADS)

    Krivit, Steven B.

    2005-03-01

    Author of the recent book, The Rebirth of Cold Fusion, and founder of New Energy Times, Steven B. Krivit presents a summary of cold fusion's, past, present and possible future. This talk will briefly review five highlights of the recent New Energy Times investigation into cold fusion research:1. Analysis of early studies that supposedly disproved cold fusion.2. Key early corroborations that supported the claims of Fleischmann and Pons.3. The evolving understanding of cold fusion reaction paths and by-products.4. A look at volumetric power density.5. Brief comparison of the progress in hot fusion research as compared to cold fusion research.New Energy Times, founded in 2000, is an independent communications company which currently specializes in reporting on cold fusion researchootnotetextReferences and copies of the presentation are available at www.newenergytimes.com/reports/aps2005.htmhttp://www.newenergytimes.com/reports/aps2005.htm. It has no affiliations with any organization, entity or party which invests in these technologies, nor any individual researcher or research facility.

  2. Cellulose binding domain fusion proteins

    DOEpatents

    Shoseyov, O.; Yosef, K.; Shpiegl, I.; Goldstein, M.A.; Doi, R.H.

    1998-02-17

    A cellulose binding domain (CBD) having a high affinity for crystalline cellulose and chitin is disclosed, along with methods for the molecular cloning and recombinant production. Fusion products comprising the CBD and a second protein are likewise described. A wide range of applications are contemplated for both the CBD and the fusion products, including drug delivery, affinity separations, and diagnostic techniques. 16 figs.

  3. Membrane fusion during poxvirus entry.

    PubMed

    Moss, Bernard

    2016-12-01

    Poxviruses comprise a large family of enveloped DNA viruses that infect vertebrates and invertebrates. Poxviruses, unlike most DNA viruses, replicate in the cytoplasm and encode enzymes and other proteins that enable entry, gene expression, genome replication, virion assembly and resistance to host defenses. Entry of vaccinia virus, the prototype member of the family, can occur at the plasma membrane or following endocytosis. Whereas many viruses encode one or two proteins for attachment and membrane fusion, vaccinia virus encodes four proteins for attachment and eleven more for membrane fusion and core entry. The entry-fusion proteins are conserved in all poxviruses and form a complex, known as the Entry Fusion Complex (EFC), which is embedded in the membrane of the mature virion. An additional membrane that encloses the mature virion and is discarded prior to entry is present on an extracellular form of the virus. The EFC is held together by multiple interactions that depend on nine of the eleven proteins. The entry process can be divided into attachment, hemifusion and core entry. All eleven EFC proteins are required for core entry and at least eight for hemifusion. To mediate fusion the virus particle is activated by low pH, which removes one or more fusion repressors that interact with EFC components. Additional EFC-interacting fusion repressors insert into cell membranes and prevent secondary infection. The absence of detailed structural information, except for two attachment proteins and one EFC protein, is delaying efforts to determine the fusion mechanism.

  4. Is there hope for fusion

    SciTech Connect

    Fowler, T.K. . Dept. of Nuclear Engineering)

    1990-04-12

    From the outset in the 1950's, fusion research has been motivated by environmental concerns as well as long-term fuel supply issues. Compared to fossil fuels both fusion and fission would produce essentially zero emissions to the atmosphere. Compared to fission, fusion reactors should offer high demonstrability of public protection from accidents and a substantial amelioration of the radioactive waste problem. Fusion still requires lengthy development, the earliest commercial deployment being likely to occur around 2025--2050. However, steady scientific progress is being made and there is a wide consensus that it is time to plan large-scale engineering development. A major international effort, called the International Thermonuclear Experimental Reactor (ITER), is being carried out under IAEA auspices to design the world's first fusion engineering test reactor, which could be constructed in the 1990's. 4 figs., 3 tabs.

  5. Adjoint affine fusion and tadpoles

    NASA Astrophysics Data System (ADS)

    Urichuk, Andrew; Walton, Mark A.

    2016-06-01

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

  6. lncRNA-Encoded Polypeptide SPAR(s) with mTORC1 to Regulate Skeletal Muscle Regeneration.

    PubMed

    Tajbakhsh, Shahragim

    2017-04-06

    Although prematurely baptized as non-coding, some lncRNAs encode polypeptides with regulatory functions that are implicated in various biological processes. Matsumoto et al. (2017) recently report in Nature that LINC00961 generates SPAR polypeptide that acts via the lysosome to suppress amino-acid-mediated mTORC1 activity, thereby modulating skeletal muscle regenerative response following injury.

  7. Information integration for data fusion

    SciTech Connect

    Bray, O.H.

    1997-01-01

    Data fusion has been identified by the Department of Defense as a critical technology for the U.S. defense industry. Data fusion requires combining expertise in two areas - sensors and information integration. Although data fusion is a rapidly growing area, there is little synergy and use of common, reusable, and/or tailorable objects and models, especially across different disciplines. The Laboratory-Directed Research and Development project had two purposes: to see if a natural language-based information modeling methodology could be used for data fusion problems, and if so, to determine whether this methodology would help identify commonalities across areas and achieve greater synergy. The project confirmed both of the initial hypotheses: that the natural language-based information modeling methodology could be used effectively in data fusion areas and that commonalities could be found that would allow synergy across various data fusion areas. The project found five common objects that are the basis for all of the data fusion areas examined: targets, behaviors, environments, signatures, and sensors. Many of the objects and the specific facts related to these objects were common across several areas and could easily be reused. In some cases, even the terminology remained the same. In other cases, different areas had their own terminology, but the concepts were the same. This commonality is important with the growing use of multisensor data fusion. Data fusion is much more difficult if each type of sensor uses its own objects and models rather than building on a common set. This report introduces data fusion, discusses how the synergy generated by this LDRD would have benefited an earlier successful project and contains a summary information model from that project, describes a preliminary management information model, and explains how information integration can facilitate cross-treaty synergy for various arms control treaties.

  8. Production of Recombinant Polypeptides Containing One GA-Module and Analysis of Their Ability to Bind to Human Albumin.

    PubMed

    Bormotova, E A; Gupalova, T V

    2016-11-01

    Surface proteins of many bacterial species interact with human serum albumin (HSA) via a special region of amino acid sequence termed GA module. For instance, surface peptostreptococcal albumin-binding protein of anaerobic bacteria Peptostreptococcus magnus contains one HSA-binding GA-module. Protein G from group G and C Streptococcus strains isolated from humans has HSA-binding region consisting of three GA-modules. HSA-binding protein containing two GA-modules was found in strains of group G Streptococcus of animal origin. We obtained two recombinant polypeptides GA1 and GA2 congaing one GA-module each. Recombinant polypeptide with two GA-modules binds HSA with a much higher affinity than polypeptides GA1 and GA2 containing one GA-module. Polypeptide with the second GAmodule more effectively binds HSA than polypeptides with the GA-module.

  9. Novel antibacterial polypeptide laparaxin produced by Lactobacillus paracasei strain NRRL B-50314 via fermentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study reports the production and characterization of a novel antibacterial polypeptide, designated laparaxin, which is secreted by Lactobacillus paracasei NRRL B-50314. Crude laparaxin has antibacterial activity against a wide variety of Gram-positive bacteria, including: lactic acid bacteria ...

  10. Self-assemble nanoparticles based on polypeptides containing C-terminal luminescent Pt-cysteine complex

    PubMed Central

    Vlakh, E. G.; Grachova, E. V.; Zhukovsky, D. D.; Hubina, A. V.; Mikhailova, A. S.; Shakirova, J. R.; Sharoyko, V. V.; Tunik, S. P.; Tennikova, T. B.

    2017-01-01

    The growing attention to the luminescent nanocarriers is strongly stimulated by their potential application as drug delivery systems and by the necessity to monitor their distribution in cells and tissues. In this communication we report on the synthesis of amphiphilic polypeptides bearing C-terminal phosphorescent label together with preparation of nanoparticles using the polypeptides obtained. The approach suggested is based on a unique and highly technological process where the new phosphorescent Pt-cysteine complex serves as initiator of the ring-opening polymerization of α-amino acid N-carboxyanhydrides to obtain the polypeptides bearing intact the platinum chromophore covalently bound to the polymer chain. It was established that the luminescent label retains unchanged its emission characteristics not only in the polypeptides but also in more complicated nanoaggregates such as the polymer derived amphiphilic block-copolymers and self-assembled nanoparticles. The phosphorescent nanoparticles display no cytotoxicity and hemolytic activity in the tested range of concentrations and easily internalize into living cells that makes possible in vivo cell visualization, including prospective application in time resolved imaging and drug delivery monitoring. PMID:28155880

  11. Antipeptide antibodies that can distinguish specific subunit polypeptides of glutamine synthetase from bean (Phaseolus vulgaris L.)

    NASA Technical Reports Server (NTRS)

    Cai, X.; Henry, R. L.; Takemoto, L. J.; Guikema, J. A.; Wong, P. P.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    The amino acid sequences of the beta and gamma subunit polypeptides of glutamine synthetase from bean (Phaseolus vulgaris L.) root nodules are very similar. However, there are small regions within the sequences that are significantly different between the two polypeptides. The sequences between amino acids 2 and 9 and between 264 and 274 are examples. Three peptides (gamma 2-9, gamma 264-274, and beta 264-274) corresponding to these sequences were synthesized. Antibodies against these peptides were raised in rabbits and purified with corresponding peptide-Sepharose affinity chromatography. Western blot analysis of polyacrylamide gel electrophoresis of bean nodule proteins demonstrated that the anti-beta 264-274 antibodies reacted specifically with the beta polypeptide and the anti-gamma 264-274 and anti-gamma 2-9 antibodies reacted specifically with the gamma polypeptide of the native and denatured glutamine synthetase. These results showed the feasibility of using synthetic peptides in developing antibodies that are capable of distinguishing proteins with similar primary structures.

  12. A role for helical intermediates in amyloid formation by natively unfolded polypeptides?

    NASA Astrophysics Data System (ADS)

    Abedini, Andisheh; Raleigh, Daniel P.

    2009-03-01

    Amyloid formation and aberrant protein aggregation have been implicated in more than 15 different human diseases and an even wider range of proteins form amyloid in vitro. From a structural perspective the proteins which form amyloid can be divided into two classes: those which adopt a compact globular fold and must presumably at least partially unfold to form amyloid and those which are unstructured in their monomeric state. Important examples of the latter include the Aβ peptide of Alzheimer's disease, atrial natriuretic factor, calcitonin, pro-calcitonin, islet amyloid polypeptide (IAPP, amylin), α-synuclein and the medin polypeptide. The kinetics of amyloid assembly are complex and typically involve a lag phase during which little or no fibril material is formed, followed by a rapid growth stage leading to the β-sheet-rich amyloid structure. Increasing evidence suggests that some natively unfolded polypeptides populate a helical intermediate during the lag phase. We propose a model in which early oligomerization is linked to helix formation and is promoted by helix-helix association. Recent work has highlighted the potential importance of polypeptide membrane interactions in amyloid formation and helical intermediates appear to play an important role here as well. Characterization of helical intermediates is experimentally challenging but new spectroscopic techniques are emerging which hold considerable promise and even have the potential to provide residue specific information.

  13. The ribosome quality control pathway can access nascent polypeptides stalled at the Sec61 translocon.

    PubMed

    von der Malsburg, Karina; Shao, Sichen; Hegde, Ramanujan S

    2015-06-15

    Cytosolic ribosomes that stall during translation are split into subunits, and nascent polypeptides trapped in the 60S subunit are ubiquitinated by the ribosome quality control (RQC) pathway. Whether the RQC pathway can also target stalls during cotranslational translocation into the ER is not known. Here we report that listerin and NEMF, core RQC components, are bound to translocon-engaged 60S subunits on native ER membranes. RQC recruitment to the ER in cultured cells is stimulated by translation stalling. Biochemical analyses demonstrated that translocon-targeted nascent polypeptides that subsequently stall are polyubiquitinated in 60S complexes. Ubiquitination at the translocon requires cytosolic exposure of the polypeptide at the ribosome-Sec61 junction. This exposure can result from either failed insertion into the Sec61 channel or partial backsliding of translocating nascent chains. Only Sec61-engaged nascent chains early in their biogenesis were relatively refractory to ubiquitination. Modeling based on recent 60S-RQC and 80S-Sec61 structures suggests that the E3 ligase listerin accesses nascent polypeptides via a gap in the ribosome-translocon junction near the Sec61 lateral gate. Thus the RQC pathway can target stalled translocation intermediates for degradation from the Sec61 channel.

  14. The ribosome quality control pathway can access nascent polypeptides stalled at the Sec61 translocon

    PubMed Central

    von der Malsburg, Karina; Shao, Sichen; Hegde, Ramanujan S.

    2015-01-01

    Cytosolic ribosomes that stall during translation are split into subunits, and nascent polypeptides trapped in the 60S subunit are ubiquitinated by the ribosome quality control (RQC) pathway. Whether the RQC pathway can also target stalls during cotranslational translocation into the ER is not known. Here we report that listerin and NEMF, core RQC components, are bound to translocon-engaged 60S subunits on native ER membranes. RQC recruitment to the ER in cultured cells is stimulated by translation stalling. Biochemical analyses demonstrated that translocon-targeted nascent polypeptides that subsequently stall are polyubiquitinated in 60S complexes. Ubiquitination at the translocon requires cytosolic exposure of the polypeptide at the ribosome–Sec61 junction. This exposure can result from either failed insertion into the Sec61 channel or partial backsliding of translocating nascent chains. Only Sec61-engaged nascent chains early in their biogenesis were relatively refractory to ubiquitination. Modeling based on recent 60S–RQC and 80S–Sec61 structures suggests that the E3 ligase listerin accesses nascent polypeptides via a gap in the ribosome–translocon junction near the Sec61 lateral gate. Thus the RQC pathway can target stalled translocation intermediates for degradation from the Sec61 channel. PMID:25877867

  15. STIR: A Pilot Study on the Bulk Properties and Morphology of Polypeptide-Grafted Brush Polymers

    DTIC Science & Technology

    2014-03-17

    the average separation distance between individual brush polymers. Therefore, we cannot assert the extent of interdigitation between the brush...density of grafted chains (e.g., in PN20-g-PBLGn) made it more difficulty for the polypeptides to facilitate interdigitation effectively. As the

  16. Ricin and Ricinus communis agglutinin subunits are all derived from a single-size polypeptide precursor.

    PubMed

    Butterworth, A G; Lord, J M

    1983-12-01

    Antibodies have been raised in rabbits against the individually purified A and B subunits of the toxic castor bean lectin, ricin, and against the A' and B' subunits of Ricinus communis agglutinin type I. Each of the antisera recognised a single polypeptide species of Mr 60 500 when maturing castor bean endosperm mRNA was translated in vitro in a rabbit-reticulocyte-derived system. When dog pancreatic microsomal vesicles were included in the translational system, each subunit antiserum precipitated a group of 66 000-68 000-Mr core-glycosylated polypeptides which had been translocated into the lumen of the vesicles. The 60 500-Mr polypeptide appeared to be a common precursor to all four individual lectin subunits since (a) its glycosylated (66 000-68 000-Mr) forms were readily detected in the endoplasmic reticulum fraction isolated from maturing castor bean endosperm and (b) pulse-chase studies showed that the glycosylated precursors disappeared from the endoplasmic reticulum fraction with the concomittant appearance of authentic lectin subunits in a soluble protein fraction which included protein body matrix components. Antiserum prepared against whole R. communis agglutinin, type I, also precipitated the 65 000-Mr precursor in vitro and in vivo, but in addition precipitated a non-glycosylated 34 000-Mr polypeptide. This smaller protein is not a lectin subunit precursor, contradicting an earlier suggestion. It is most probably a precursor to the 2-S albumin storage proteins found in castor bean endosperm protein bodies.

  17. Novel antibacterial polypeptide produced by Lactobacillus paracasei strain NRRL B-50314

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study reports the production and characterization of a novel antibacterial polypeptide, designated as laparaxin, which is secreted by Lactobacillus paracasei NRRL B-50314. The crude laparaxin has antibacterial activity against a range of Gram-positive bacteria including the following: lactic a...

  18. Self-assemble nanoparticles based on polypeptides containing C-terminal luminescent Pt-cysteine complex

    NASA Astrophysics Data System (ADS)

    Vlakh, E. G.; Grachova, E. V.; Zhukovsky, D. D.; Hubina, A. V.; Mikhailova, A. S.; Shakirova, J. R.; Sharoyko, V. V.; Tunik, S. P.; Tennikova, T. B.

    2017-02-01

    The growing attention to the luminescent nanocarriers is strongly stimulated by their potential application as drug delivery systems and by the necessity to monitor their distribution in cells and tissues. In this communication we report on the synthesis of amphiphilic polypeptides bearing C-terminal phosphorescent label together with preparation of nanoparticles using the polypeptides obtained. The approach suggested is based on a unique and highly technological process where the new phosphorescent Pt-cysteine complex serves as initiator of the ring-opening polymerization of α-amino acid N-carboxyanhydrides to obtain the polypeptides bearing intact the platinum chromophore covalently bound to the polymer chain. It was established that the luminescent label retains unchanged its emission characteristics not only in the polypeptides but also in more complicated nanoaggregates such as the polymer derived amphiphilic block-copolymers and self-assembled nanoparticles. The phosphorescent nanoparticles display no cytotoxicity and hemolytic activity in the tested range of concentrations and easily internalize into living cells that makes possible in vivo cell visualization, including prospective application in time resolved imaging and drug delivery monitoring.

  19. Dynamics of the formation of a hydrogel by a pathogenic amyloid peptide: islet amyloid polypeptide

    PubMed Central

    Jean, Létitia; Lee, Chiu Fan; Hodder, Peter; Hawkins, Nick; Vaux, David J.

    2016-01-01

    Many chronic degenerative diseases result from aggregation of misfolded polypeptides to form amyloids. Many amyloidogenic polypeptides are surfactants and their assembly can be catalysed by hydrophobic-hydrophilic interfaces (an air-water interface in-vitro or membranes in-vivo). We recently demonstrated the specificity of surface-induced amyloidogenesis but the mechanisms of amyloidogenesis and more specifically of adsorption at hydrophobic-hydrophilic interfaces remain poorly understood. Thus, it is critical to determine how amyloidogenic polypeptides behave at interfaces. Here we used surface tensiometry, rheology and electron microscopy to demonstrate the complex dynamics of gelation by full-length human islet amyloid polypeptide (involved in type II diabetes) both in the bulk solution and at hydrophobic-hydrophilic interfaces (air-water interface and phospholipids). We show that the hydrogel consists of a 3D supramolecular network of fibrils. We also assessed the role of solvation and dissected the evolution over time of the assembly processes. Amyloid gelation could have important pathological consequences for membrane integrity and cellular functions. PMID:27535008

  20. Structural variation and inhibitor binding in polypeptide deformylase from four different bacterial species.

    PubMed

    Smith, Kathrine J; Petit, Chantal M; Aubart, Kelly; Smyth, Martin; McManus, Edward; Jones, Jo; Fosberry, Andrew; Lewis, Ceri; Lonetto, Michael; Christensen, Siegfried B

    2003-02-01

    Polypeptide deformylase (PDF) catalyzes the deformylation of polypeptide chains in bacteria. It is essential for bacterial cell viability and is a potential antibacterial drug target. Here, we report the crystal structures of polypeptide deformylase from four different species of bacteria: Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, and Escherichia coli. Comparison of these four structures reveals significant overall differences between the two Gram-negative species (E. coli and H. influenzae) and the two Gram-positive species (S. pneumoniae and S. aureus). Despite these differences and low overall sequence identity, the S1' pocket of PDF is well conserved among the four enzymes studied. We also describe the binding of nonpeptidic inhibitor molecules SB-485345, SB-543668, and SB-505684 to both S. pneumoniae and E. coli PDF. Comparison of these structures shows similar binding interactions with both Gram-negative and Gram-positive species. Understanding the similarities and subtle differences in active site structure between species will help to design broad-spectrum polypeptide deformylase inhibitor molecules.

  1. Coordinating Electrical Activity of the Heart: Ankyrin Polypeptides in Human Cardiac Disease

    PubMed Central

    Curran, Jerry; Mohler, Peter J

    2011-01-01

    Introduction Over the past ten years, ankyrin polypeptides have emerged as critical players in cardiac excitation-contraction coupling. Once thought to solely play only a structural role, loss-of-function variants in genes encoding ankyrin polypeptides have highlighted how this protein mediates the proper subcellular localization of the various electrical components of the excitation-contraction coupling machinery. A large body of evidence has revealed how the disruption of this localization is the primary cause of various cardiomyopathies, ranging from long QT syndrome 4, to sinus node disease, to more common forms of arrhythmias. Areas Covered This review details the varied roles that ankyrin polypeptides play in excitation-contraction coupling in the heart and the development of ankyrin-specific cardiomyopathies. It will further discuss how ankyrin polypeptides may be involved in structural and electrical remodeling of the heart, post-myocardial infarct. Attention is given to how ankyrin interactions with membrane bound ion channels may regulate these channels’ response to stimuli. Special attention is given to exciting new data, which may offer the potential for unique therapies, for not only combating heart disease, but which also holds promise for wider applications to various disease states. Expert Opinion The ankyrin family of adapter proteins is emerging as an intimate player in cardiac excitation-contraction coupling. Until recently, these proteins have gone largely unappreciated for their importance in proper cardiac function. New insights into how these proteins function within the heart are offering potentially new avenues for therapies against cardiomyopathy. PMID:21457127

  2. Biomimetic assembly of polypeptide-stabilized CaCO(3) nanoparticles.

    PubMed

    Zhang, Zhongping; Gao, Daming; Zhao, Hui; Xie, Chenggen; Guan, Guijian; Wang, Dapeng; Yu, Shu-Hong

    2006-05-04

    In this paper, we report a simple polypeptide-directed strategy for fabricating large spherical assembly of CaCO(3) nanoparticles. Stepwise growth and assembly of a large number of nanoparticles have been observed, from the formation of an amorphous liquidlike CaCO(3)-polypeptide precursor, to the crystallization and stabilization of polypeptide-capped nanoparticles, and eventually, the spherical assembly of nanoparticles. The "soft" poly(aspartate)-capping layer binding on a nanoparticle surface resulted in the unusual soft nature of nanoparticle assembly, providing a reservoir of primary nanoparticles with a moderate mobility, which is the basis of a new strategy for reconstructing nanoparticle assembly into complex nanoparticle architectures. Moreover, the findings of the secondary assembly of nanoparticle microspheres and the morphology transformation of nanoparticle assembly demonstrate a flexible and controllable pathway for manipulating the shapes and structures of nanoparticle assembly. In addition, the combination of the polypeptide with a double hydrophilic block copolymer (DHBC) allows it to possibly further control the shape and complexity of the nanoparticle assembly. A clear perspective is shown here that more complex nanoparticle materials could be created by using "soft" biological proteins or peptides as a mediating template at the organic-inorganic interface.

  3. The Beads of Translation: Using Beads to Translate mRNA into a Polypeptide Bracelet

    ERIC Educational Resources Information Center

    Dunlap, Dacey; Patrick, Patricia

    2012-01-01

    During this activity, by making beaded bracelets that represent the steps of translation, students simulate the creation of an amino acid chain. They are given an mRNA sequence that they translate into a corresponding polypeptide chain (beads). This activity focuses on the events and sites of translation. The activity provides students with a…

  4. Fusion heating technology

    SciTech Connect

    Cole, A.J.

    1982-06-01

    John Lawson established the criterion that in order to produce more energy from fusion than is necessary to heat the plasma and replenish the radiation losses, a minimum value for both the product of plasma density and confinement time t, and the temperature must be achieved. There are two types of plasma heating: neutral beam and electromagnetic wave heating. A neutral beam system is shown. Main development work on negative ion beamlines has focused on the difficult problem of the production of high current sources. The development of a 30 keV-1 ampere multisecond source module is close to being accomplished. In electromagnetic heating, the launcher, which provides the means of coupling the power to the plasma, is most important. The status of heating development is reviewed. Electron cyclotron resonance heating (ECRH), lower hybrid heating (HHH), and ion cyclotron resonance heating (ICRH) are reviewed.

  5. Fusion Power Demonstration III

    SciTech Connect

    Lee, J.D.

    1985-07-01

    This is the third in the series of reports covering the Fusion Power Demonstration (FPD) design study. This volume considers the FPD-III configuration that incorporates an octopole end plug. As compared with the quadrupole end-plugged designs of FPD-I and FPD-II, this octopole configuration reduces the number of end cell magnets and shortens the minimum ignition length of the central cell. The end-cell plasma length is also reduced, which in turn reduces the size and cost of the end cell magnets and shielding. As a contiuation in the series of documents covering the FPD, this report does not stand alone as a design description of FPD-III. Design details of FPD-III subsystems that do not differ significantly from those of the FPD-II configuration are not duplicated in this report.

  6. Fusion pumped light source

    DOEpatents

    Pappas, Daniel S.

    1989-01-01

    Apparatus is provided for generating energy in the form of light radiation. A fusion reactor is provided for generating a long, or continuous, pulse of high-energy neutrons. The neutron flux is coupled directly with the lasing medium. The lasing medium includes a first component selected from Group O of the periodic table of the elements and having a high inelastic scattering cross section. Gamma radiation from the inelastic scattering reactions interacts with the first component to excite the first component, which decays by photon emission at a first output wavelength. The first output wavelength may be shifted to a second output wavelength using a second liquid component responsive to the first output wavelength. The light outputs may be converted to a coherent laser output by incorporating conventional optics adjacent the laser medium.

  7. Fusion pumped laser

    DOEpatents

    Pappas, Daniel S.

    1989-01-01

    Apparatus is provided for generating energy in the form of laser radiation. A tokamak fusion reactor is provided for generating a long, or continuous, pulse of high-energy neutrons. The tokamak design provides a temperature and a magnetic field which is effective to generate a neutron flux of at least 10.sup.15 neutrons/cm.sup.2.s. A conversion medium receives neutrons from the tokamak and converts the high-energy neutrons to an energy source with an intensity and an energy effective to excite a preselected lasing medium. The energy source typically comprises fission fragments, alpha particles, and radiation from a fission event. A lasing medium is provided which is responsive to the energy source to generate a population inversion which is effective to support laser oscillations for generating output radiation.

  8. Multiple shell fusion targets

    DOEpatents

    Lindl, J.D.; Bangerter, R.O.

    1975-10-31

    Multiple shell fusion targets for use with electron beam and ion beam implosion systems are described. The multiple shell targets are of the low-power type and use a separate relatively low Z, low density ablator at large radius for the outer shell, which reduces the focusing and power requirements of the implosion system while maintaining reasonable aspect ratios. The targets use a high Z, high density pusher shell placed at a much smaller radius in order to obtain an aspect ratio small enough to protect against fluid instability. Velocity multiplication between these shells further lowers the power requirements. Careful tuning of the power profile and intershell density results in a low entropy implosion which allows breakeven at low powers. For example, with ion beams as a power source, breakeven at 10-20 Terrawatts with 10 MeV alpha particles for imploding a multiple shell target can be accomplished.

  9. Fusion reactor pumped laser

    DOEpatents

    Jassby, D.L.

    1987-09-04

    A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam. 10 figs.

  10. Microwave superheaters for fusion

    SciTech Connect

    Campbell, R.B.; Hoffman, M.A.; Logan, B.G.

    1987-10-16

    The microwave superheater uses the synchrotron radiation from a thermonuclear plasma to heat gas seeded with an alkali metal to temperatures far above the temperature of material walls. It can improve the efficiency of the Compact Fusion Advanced Rankine (CFAR) cycle described elsewhere in these proceedings. For a proof-of-principle experiment using helium, calculations show that a gas superheat ..delta..T of 2000/sup 0/K is possible when the wall temperature is maintained at 1000/sup 0/K. The concept can be scaled to reactor grade systems. Because of the need for synchrotron radiation, the microwave superheater is best suited for use with plasmas burning an advanced fuel such as D-/sup 3/He. 5 refs.

  11. Prospects for bubble fusion

    SciTech Connect

    Nigmatulin, R.I.; Lahey, R.T. Jr.

    1995-09-01

    In this paper a new method for the realization of fusion energy is presented. This method is based on the superhigh compression of a gas bubble (deuterium or deuterium/thritium) in heavy water or another liquid. The superhigh compression of a gas bubble in a liquid is achieved through forced non-linear, non-periodic resonance oscillations using moderate amplitudes of forcing pressure. The key feature of this new method is a coordination of the forced liquid pressure change with the change of bubble volume. The corresponding regime of the bubble oscillation has been called {open_quotes}basketball dribbling (BD) regime{close_quotes}. The analytical solution describing this process for spherically symmetric bubble oscillations, neglecting dissipation and compressibility of the liquid, has been obtained. This solution shown no limitation on the supercompression of the bubble and the corresponding maximum temperature. The various dissipation mechanisms, including viscous, conductive and radiation heat losses have been considered. It is shown that in spite of these losses it is possible to achieve very high gas bubble temperatures. This because the time duration of the gas bubble supercompression becomes very short when increasing the intensity of compression, thus limiting the energy losses. Significantly, the calculated maximum gas temperatures have shown that nuclear fusion may be possible. First estimations of the affect of liquid compressibility have been made to determine possible limitations on gas bubble compression. The next step will be to investigate the role of interfacial instability and breaking down of the bubble, shock wave phenomena around and in the bubble and mutual diffusion of the gas and the liquid.

  12. Soldier systems sensor fusion

    NASA Astrophysics Data System (ADS)

    Brubaker, Kathryne M.

    1998-08-01

    This paper addresses sensor fusion and its applications in emerging Soldier Systems integration and the unique challenges associated with the human platform. Technology that,provides the highest operational payoff in a lightweight warrior system must not only have enhanced capabilities, but have low power components resulting in order of magnitude reductions coupled with significant cost reductions. These reductions in power and cost will be achieved through partnership with industry and leveraging of commercial state of the art advancements in microelectronics and power sources. As new generation of full solution fire control systems (to include temperature, wind and range sensors) and target acquisition systems will accompany a new generation of individual combat weapons and upgrade existing weapon systems. Advanced lightweight thermal, IR, laser and video senors will be used for surveillance, target acquisition, imaging and combat identification applications. Multifunctional sensors will provide embedded training features in combat configurations allowing the soldier to 'train as he fights' without the traditional cost and weight penalties associated with separate systems. Personal status monitors (detecting pulse, respiration rate, muscle fatigue, core temperature, etc.) will provide commanders and highest echelons instantaneous medical data. Seamless integration of GPS and dead reckoning (compass and pedometer) and/or inertial sensors will aid navigation and increase position accuracy. Improved sensors and processing capability will provide earlier detection of battlefield hazards such as mines, enemy lasers and NBC (nuclear, biological, chemical) agents. Via the digitized network the situational awareness database will automatically be updated with weapon, medical, position and battlefield hazard data. Soldier Systems Sensor Fusion will ultimately establish each individual soldier as an individual sensor on the battlefield.

  13. LiWall Fusion - The New Concept of Magnetic Fusion

    SciTech Connect

    L.E. Zakharov

    2011-01-12

    Utilization of the outstanding abilities of a liquid lithium layer in pumping hydrogen isotopes leads to a new approach to magnetic fusion, called the LiWall Fusion. It relies on innovative plasma regimes with low edge density and high temperature. The approach combines fueling the plasma by neutral injection beams with the best possible elimination of outside neutral gas sources, which cools down the plasma edge. Prevention of cooling the plasma edge suppresses the dominant, temperature gradient related turbulence in the core. Such an approach is much more suitable for controlled fusion than the present practice, relying on high heating power for compensating essentially unlimited turbulent energy losses.

  14. Cloning, expression and properties of porcine trachea UDP-galnac: polypeptide N-acetylgalactosaminyl transferase.

    PubMed

    Sangadala, Sreedhara; Swain, Ja Baris; McNear, Adrian; Mendicino, Joseph

    2004-11-01

    A UDP-GalNAc:polypeptide N-acetyl-galactosaminyl transferase which catalyses the transfer of GalNAc from UDP-GalNAc to serine and threonine residues in mucin polypeptide chains was purified to homogeneity from swine trachea epithelium (Mendicino J, Sangadala S: Mol Cell Biochem 185: 135-145, 1998). Peptides obtained by proteolysis of the purified enzyme were isolated, sequenced and used to prepare degenerate oligonucleotide primers. Amplified segments of a gene encoding GalNAc transferase were synthesised using the primers and a swine trachea epithelial cDNA library. Selected cDNA fragments were then used to screen the cDNA library, and a clone containing an open reading frame encoding 559 amino acids was isolated. The predicted amino acid sequence contains type II transmembrane region, three potential N-glycosylation sites as well as all of the isolated peptide sequences. The nucleotide sequence and predicted primary protein structure of the transferase were very similar to those of type T-1 GalNAc transferases. The isolated clone was transiently expressed in COS 7 cells and the recombinant enzyme, which contained an N-terminal hexa-histidine tag, was purified to homogeneity and its enzymatic properties were examined. The Vmax of the recombinant enzyme, 2.08 micromol/(min mg), was nearly the same as the native enzyme, 2.12 micromol/(min mg), when assayed with partially deglycosylated mucins as glycosyl acceptors. Both enzymes showed much higher activities when assayed with peptides prepared by limited acid hydrolysis of incompletely deglycosylated Cowper's gland, swine, and human respiratory mucins and tryptic peptides isolated from deglycosylated mucin polypeptide chains. However, as noted earlier (Mendicino J, Sangadala S: Mol Cell Biochem 185: 135-145, 1998), these enzymes showed very little activity with completely deglycosylated mucin polypeptide chains. When completely deglycosylated polypeptide chains were partially glycosylated by incubation with microsome

  15. A two-step enzymatic glycosylation of polypeptides with complex N-glycans

    PubMed Central

    Lomino, Joseph V.; Naegeli, Andreas; Orwenyo, Jared; Amin, Mohammed N.; Aebi, Markus; Wang, Lai-Xi

    2013-01-01

    A chemoenyzmatic method for direct glycosylation of polypeptides is described. The method consists of two site-specific enzymatic glycosylation steps: introduction of a glucose moiety at the consensus N-glycosylation sequence (NXS/T) in a polypeptide by an N-glycosyltransferase (NGT) and attachment of a complex N-glycan to the glucose primer by an endoglycosidase (ENGase)-catalyzed transglycosylation. Our experiments demonstrated that a relatively small excess of the UDP-Glc (the donor substrate) was sufficient for an effective glucosylation of polypeptides by the NGT, and different high-mannose and complex type N-glycans could be readily transferred to the glucose moiety by ENGases to provide full-size glycopeptides. The usefulness of the chemoenzymatic method was exemplified by an efficient synthesis of a complex glycoform of polypeptide C34, a potent HIV inhibitor derived from HIV-1 gp41. A comparative study indicated that the Glc-peptide was equally efficient as the natural GlcNAc-peptide to serve as an acceptor in the transglycosylation with sugar oxazoline as the donor substrate. Interestingly, the Glc–Asn linked glycopeptide was completely resistant to PNGase F digestion, in contrast to the GlcNAc–Asn linked natural glycopeptide that is an excellent substrate for hydrolysis. In addition, the Glc–Asn linked glycopeptide showed at least 10-fold lower hydrolytic activity toward Endo-M than the natural GlcNAc–Asn linked glycopeptide. The chemoenzymatic glycosylation method described here provides an efficient way to introducing complex N-glycans into polypeptides, for gain of novel properties that could be valuable for drug discovery. PMID:23477942

  16. Inhibition of malaria parasite invasion of human erythrocytes by a lymphocyte membrane polypeptide.

    PubMed

    Benzaquen-Geffin, R; Milner, Y; Ginsburg, H

    1987-02-01

    Extraction by boiling of the buffy coat of human blood yields a protein solution which inhibits the propagation of the human malaria parasite Plasmodium falciparum in culture with a 50% inhibitory dose of 105 micrograms of protein per ml. The inhibitory activity is associated exclusively with the lymphocytes and affects solely the invasion of erythrocytes by free merozoites. Boiled extracts of isolated lymphocytes had a 50% inhibitory dose of 22 micrograms/ml. Fractionation of surface-labeled or pronase-treated lymphocytes revealed that the antimalarial lymphocyte factor is associated with the intracellular aspect of the membrane fraction and is probably not involved in the host defense system against malaria. Further purification by salt extraction, ion-exchange chromatography, molecular gel filtration, and electroelution from lithium dodecyl sulfate-polyacrylamide gels resulted in 300- to 550-fold purification, i.e., a 50% inhibitory dose of 40 to 70 ng/ml. All inhibitory fractions contained a 48-kilodalton polypeptide which eluted from a gel filtration column as a 400-kilodalton species, implying multimeric association. Some 6,000 molecules of the 48-kilodalton polypeptide bind with high affinity to one merozoite, the free form of the parasite. The Kd of 0.1 to 0.5 nM for the binding of the 48-kilodalton polypeptide correlated well with the 50% inhibitory dose of 0.3 to 0.4 nM obtained with purified active antimalarial lymphocyte factor. We therefore suggest that the 48-kilodalton polypeptide partially purified from lymphocyte membranes is the antimalarial lymphocyte factor and that it exerts its inhibitory activity by binding to merozoites, thereby preventing their invasion into erythrocytes. The antimalarial lymphocyte factor or a polypeptide sequence thereof could serve for further probing of invasion at the molecular level.

  17. Synthesis of gluten-forming polypeptides. 1. Biosynthesis of gliadins and glutenin subunits.

    PubMed

    Abonyi, Tibor; Király, István; Tömösközi, Sándor; Baticz, Orsolya; Guóth, Adrienn; Gergely, Szilveszter; Scholz, Eva; Lásztity, Demeter; Lásztity, Radomir

    2007-05-02

    Five winter wheat cultivars--GK Othalom (HMW-GS composition 2*, 7+8, 5+10), Ukrainka (1, 7+8, 5+10), Palotás (2*, 7+9, 5+10), Ködmön (2*, 7+8, 5+10), and Csongrád (2*, 7+9, 2+12)--grown in Hungary and harvested in the year 2005 were studied. The biosynthesis of gluten-forming polypeptides was followed starting at the 12th day after anthesis to the 53rd. Fresh kernel weight, moisture, and dry matter content of fresh kernels and gliadin and glutenin contents were determined. Gliadin components, total amounts of HMW and LMW polypeptides, and individual HMW polypeptides were determined using a RP-HPLC technique. Although considerable quantitative differences were observed concerning the content of total protein, gliadin, glutenin, and individual gluten-forming polypeptides, the character of accumulation of protein components--determined on the basis protein mass/kernel--was the same for the all of the cultivars studied and could be presented by a sigmoid curve. Small quantities of the gliadin and glutenin monomers may be detected in early stages of kernel development, but the bulk of these proteins is synthesized in later stages of development. It is generally suggested by specialists that the formation and accumulation of glutenin polymers starts later than the synthesis of monomers. Experimental data presented in this paper confirm this suggestion and show that in the first phase of protein synthesis the monomers are in "free" form; polymeric glutenin is detected only later. HMW glutenin subunits are synthesized synchronously, and quantitatively the polypeptides coded by chromosomes D and B dominate.

  18. Inhibition of malaria parasite invasion of human erythrocytes by a lymphocyte membrane polypeptide.

    PubMed Central

    Benzaquen-Geffin, R; Milner, Y; Ginsburg, H

    1987-01-01

    Extraction by boiling of the buffy coat of human blood yields a protein solution which inhibits the propagation of the human malaria parasite Plasmodium falciparum in culture with a 50% inhibitory dose of 105 micrograms of protein per ml. The inhibitory activity is associated exclusively with the lymphocytes and affects solely the invasion of erythrocytes by free merozoites. Boiled extracts of isolated lymphocytes had a 50% inhibitory dose of 22 micrograms/ml. Fractionation of surface-labeled or pronase-treated lymphocytes revealed that the antimalarial lymphocyte factor is associated with the intracellular aspect of the membrane fraction and is probably not involved in the host defense system against malaria. Further purification by salt extraction, ion-exchange chromatography, molecular gel filtration, and electroelution from lithium dodecyl sulfate-polyacrylamide gels resulted in 300- to 550-fold purification, i.e., a 50% inhibitory dose of 40 to 70 ng/ml. All inhibitory fractions contained a 48-kilodalton polypeptide which eluted from a gel filtration column as a 400-kilodalton species, implying multimeric association. Some 6,000 molecules of the 48-kilodalton polypeptide bind with high affinity to one merozoite, the free form of the parasite. The Kd of 0.1 to 0.5 nM for the binding of the 48-kilodalton polypeptide correlated well with the 50% inhibitory dose of 0.3 to 0.4 nM obtained with purified active antimalarial lymphocyte factor. We therefore suggest that the 48-kilodalton polypeptide partially purified from lymphocyte membranes is the antimalarial lymphocyte factor and that it exerts its inhibitory activity by binding to merozoites, thereby preventing their invasion into erythrocytes. The antimalarial lymphocyte factor or a polypeptide sequence thereof could serve for further probing of invasion at the molecular level. Images PMID:3542831

  19. pH responsiveness of fibrous assemblies of repeat-sequence amphipathic α-helix polypeptides

    PubMed Central

    Takei, Toshiaki; Tsumoto, Kouhei; Okonogi, Atsuhito; Kimura, Akiko; Kojima, Shuichi; Yazaki, Kazumori; Takei, Tsunetomo; Ueda, Takuya; Miura, Kin-ichiro

    2015-01-01

    We reported previously that our designed polypeptide α3 (21 residues), which has three repeats of a seven-amino-acid sequence (LETLAKA)3, forms not only an amphipathic α-helix structure but also long fibrous assemblies in aqueous solution. To address the relationship between the electrical states of the polypeptide and its α-helix and fibrous assembly formation, we characterized mutated polypeptides in which charged amino acid residues of α3 were replaced with Ser. We prepared the following polypeptides: 2Sα3 (LSTLAKA)3, in which all Glu residues were replaced with Ser residues; 6Sα3 (LETLASA)3, in which all Lys residues were replaced with Ser; and 2S6Sα3 (LSTLASA)3; in which all Glu and Lys residues were replaced with Ser. In 0.1M KCl, 2Sα3 formed an α-helix under basic conditions and 6Sα3 formed an α-helix under acid conditions. In 1M KCl, they both formed α-helices under a wide pH range. In addition, 2Sα3 and 6Sα3 formed fibrous assemblies under the same buffer conditions in which they formed α-helices. α-Helix and fibrous assembly formation by these polypeptides was reversible in a pH-dependent manner. In contrast, 2S6Sα3 formed an α-helix under basic conditions in 1M KCl. Taken together, these findings reveal that the charge states of the charged amino acid residues and the charge state of the Leu residue located at the terminus play an important role in α-helix formation. PMID:25694229

  20. Analytical performance evaluation for autonomous sensor fusion

    NASA Astrophysics Data System (ADS)

    Chang, K. C.

    2008-04-01

    A distributed data fusion system consists of a network of sensors, each capable of local processing and fusion of sensor data. There has been a great deal of work in developing distributed fusion algorithms applicable to a network centric architecture. Currently there are at least a few approaches including naive fusion, cross-correlation fusion, information graph fusion, maximum a posteriori (MAP) fusion, channel filter fusion, and covariance intersection fusion. However, in general, in a distributed system such as the ad hoc sensor networks, the communication architecture is not fixed. Each node has knowledge of only its local connectivity but not the global network topology. In those cases, the distributed fusion algorithm based on information graph type of approach may not scale due to its requirements to carry long pedigree information for decorrelation. In this paper, we focus on scalable fusion algorithms and conduct analytical performance evaluation to compare their performance. The goal is to understand the performance of those algorithms under different operating conditions. Specifically, we evaluate the performance of channel filter fusion, Chernoff fusion, Shannon Fusion, and Battachayya fusion algorithms. We also compare their results to NaÃve fusion and "optimal" centralized fusion algorithms under a specific communication pattern.

  1. Fusion Simulation Project Workshop Report

    NASA Astrophysics Data System (ADS)

    Kritz, Arnold; Keyes, David

    2009-03-01

    The mission of the Fusion Simulation Project is to develop a predictive capability for the integrated modeling of magnetically confined plasmas. This FSP report adds to the previous activities that defined an approach to integrated modeling in magnetic fusion. These previous activities included a Fusion Energy Sciences Advisory Committee panel that was charged to study integrated simulation in 2002. The report of that panel [Journal of Fusion Energy 20, 135 (2001)] recommended the prompt initiation of a Fusion Simulation Project. In 2003, the Office of Fusion Energy Sciences formed a steering committee that developed a project vision, roadmap, and governance concepts [Journal of Fusion Energy 23, 1 (2004)]. The current FSP planning effort involved 46 physicists, applied mathematicians and computer scientists, from 21 institutions, formed into four panels and a coordinating committee. These panels were constituted to consider: Status of Physics Components, Required Computational and Applied Mathematics Tools, Integration and Management of Code Components, and Project Structure and Management. The ideas, reported here, are the products of these panels, working together over several months and culminating in a 3-day workshop in May 2007.

  2. Control of mechanically activated polymersome fusion: Factors affecting fusion

    DOE PAGES

    Henderson, Ian M.; Paxton, Walter F.

    2014-12-15

    Previously we have studied the mechanically-activated fusion of extruded (200 nm) polymer vesicles into giant polymersomes using agitation in the presence of salt. In this study we have investigated several factors contributing to this phenomenon, including the effects of (i) polymer vesicle concentration, (ii) agitation speed and duration, and iii) variation of the salt and its concentration. It was found that increasing the concentration of the polymer dramatically increases the production of giant vesicles through the increased collisions of polymersomes. Our investigations also found that increasing the frequency of agitation increased the efficiency of fusion, though ultimately limited the sizemore » of vesicle which could be produced due to the high shear involved. Finally it was determined that salt-mediation of the fusion process was not limited to NaCl, but is instead a general effect facilitated by the presence of solvated ionic compounds, albeit with different salts initiating fusion at different concentration.« less

  3. Control of mechanically activated polymersome fusion: Factors affecting fusion

    SciTech Connect

    Henderson, Ian M.; Paxton, Walter F.

    2014-12-15

    Previously we have studied the mechanically-activated fusion of extruded (200 nm) polymer vesicles into giant polymersomes using agitation in the presence of salt. In this study we have investigated several factors contributing to this phenomenon, including the effects of (i) polymer vesicle concentration, (ii) agitation speed and duration, and iii) variation of the salt and its concentration. It was found that increasing the concentration of the polymer dramatically increases the production of giant vesicles through the increased collisions of polymersomes. Our investigations also found that increasing the frequency of agitation increased the efficiency of fusion, though ultimately limited the size of vesicle which could be produced due to the high shear involved. Finally it was determined that salt-mediation of the fusion process was not limited to NaCl, but is instead a general effect facilitated by the presence of solvated ionic compounds, albeit with different salts initiating fusion at different concentration.

  4. Advanced fusion concepts: project summaries

    SciTech Connect

    1980-12-01

    This report contains descriptions of the activities of all the projects supported by the Advanced Fusion Concepts Branch of the Office of Fusion Energy, US Department of Energy. These descriptions are project summaries of each of the individual projects, and contain the following: title, principle investigators, funding levels, purpose, approach, progress, plans, milestones, graduate students, graduates, other professional staff, and recent publications. Information is given for each of the following programs: (1) reverse-field pinch, (2) compact toroid, (3) alternate fuel/multipoles, (4) stellarator/torsatron, (5) linear magnetic fusion, (6) liners, and (7) Tormac. (MOW)

  5. Effect of aniseikonia on fusion.

    PubMed

    Sharma, P; Prakash, P

    1991-01-01

    Physiological aniseikonia is the basis of stereopsis but beyond certain limits it becomes an obstacle to fusion. It is not well established as to how much aniseikonia can be tolerated by the fusional mechanism. Different tests under different testing conditions have given a wide range of variation. On the synoptophore we had observed tolerance upto 35% aniseikonia in some cases. Under more physiological conditions on a polaroid dissociation stereoprojector we observed lesser baseline fusional vergences but tolerance in about 70% of the cases upto 30% aniseikonia while 25% could tolerate even 35% aniseikonia. However we realise that these indicate the maximal potential and not the symptom free tolerable limits.

  6. The path to fusion power†

    PubMed Central

    Smith, Chris Llewellyn; Cowley, Steve

    2010-01-01

    The promise, status and challenges of developing fusion power are outlined. The key physics and engineering principles are described and recent progress quantified. As the successful demonstration of 16 MW of fusion in 1997 in the Joint European Torus showed, fusion works. The central issue is therefore to make it work reliably and economically on the scale of a power station. We argue that to meet this challenge in 30 years we must follow the aggressive programme known as the ‘Fast Track to Fusion’. This programme is described in some detail. PMID:20123748

  7. Generalized Chernoff Fusion Approximation for Practical Distributed Data Fusion

    DTIC Science & Technology

    2009-07-01

    Generalized Chernoff Fusion Approximation for Practical Distributed Data Fusion William J. Farrell III R&D Department Adaptive Methods , Inc...independence or modify legacy systems with pedigree tagging techniques . Leveraging the well- known Covariance Intersection algorithm, its generalization...Adaptive Methods , Inc.,Centreville, VA , , 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR

  8. Polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and polynucleotides encoding same

    DOEpatents

    Morant, Marc

    2017-02-07

    The present invention relates to isolated polypeptides having beta-glucosidase activity, beta-xylosidase activity, or beta-glucosidase and beta-xylosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

  9. [Preparation and the biological effect of fusion protein GLP-1-exendin-4/ IgG4(Fc) fusion protein as long acting GLP-1 receptor agonist].

    PubMed

    Zheng, Yun-cheng

    2015-12-01

    GLP-1 has a variety of anti-diabetic effects. However, native GLP-1 is not suitable for treatment of diabetes due to its short half-life (t½, 2-5 min). Exendin-4 is a polypeptide isolated from lizard saliva, which can bind to GLP-1 receptor, produce physiological effects similar to GLP-1, t½ up to 2.5 h, therefore, we developed a long-lasting GLP-1 receptor agonists and GLP-1-exendin-4 fusion IgG4 Fc [GLP-1-exendin-4/ IgG4(Fc)]. We constructed the eukaryotic expression vector of human GLP-1-exendin-4/IgG4(Fc)-pOptiVEC- TOPO by gene recombination technique and expressed the fusion protein human GLP-1-IgG4 (Fc) in CHO/DG44 cells. The fusion protein stimulated the INS-1 cells secretion of insulin, GLP-1, exendin-4 and fusion protein in CD1 mice pharmacokinetic experiments, as well as GLP-1, exendin-4 and fusion protein did anti-diabetic effect on streptozotocin induced mice. Results demonstrated that the GLP-1-exendin-4/IgG4(Fc) positive CHO/DG44 clones were chosen and the media from these positive clones. Western blotting showed that one protein band was found to match well with the predicted relative molecular mass of human GLP-1-exendin-4/IgG4(Fc). Insulin RIA showed that GLP-1-exendin-4/IgG4(Fc) dose-dependently stimulated insulin secretion from INS-1 cells. Pharmacokinetic studies in CD1 mice showed that with intraperitoneal injection (ip), the fusion protein peaked at 30 min in circulation and maintained a plateau for 200 h. Natural biological half-life of exendin-4 was (1.39 ± 0.28) h, GLP-1 in vivo t½ 4 min, indicating that fusion protein has long-lasting effects on the modulation of glucose homeostasis. GLP-1-exendin-4/IgG4(Fc) was found to be effective in reducing the incidence of diabetes in multiple-low-dose streptozotocin-induced diabetes in mice, longer duration of the biological activity of the fusion protein. The biological activity was significantly higher than that of GLP-1 and exendin-4. GLP-1-exendin-4/IgG4(Fc) has good anti-diabetic activity

  10. Characterization of fusion genes and the significantly expressed fusion isoforms in breast cancer by hybrid sequencing.

    PubMed

    Weirather, Jason L; Afshar, Pegah Tootoonchi; Clark, Tyson A; Tseng, Elizabeth; Powers, Linda S; Underwood, Jason G; Zabner, Joseph; Korlach, Jonas; Wong, Wing Hung; Au, Kin Fai

    2015-10-15

    We developed an innovative hybrid sequencing approach, IDP-fusion, to detect fusion genes, determine fusion sites and identify and quantify fusion isoforms. IDP-fusion is the first method to study gene fusion events by integrating Third Generation Sequencing long reads and Second Generation Sequencing short reads. We applied IDP-fusion to PacBio data and Illumina data from the MCF-7 breast cancer cells. Compared with the existing tools, IDP-fusion detects fusion genes at higher precision and a very low false positive rate. The results show that IDP-fusion will be useful for unraveling the complexity of multiple fusion splices and fusion isoforms within tumorigenesis-relevant fusion genes.

  11. Different populations of vasoactive intestinal polypeptide-immunoreactive interneurons are specialized to control pyramidal cells or interneurons in the hippocampus.

    PubMed

    Acsády, L; Görcs, T J; Freund, T F

    1996-07-01

    The postsynaptic targets of three vasoactive intestinal polypeptide-containing GABAergic interneuron types were examined in the rat hippocampus. Two of them showed remarkable target selectivity for other GABAergic neurons, while the third contacted the somata and proximal dendrites of pyramidal cells. Vasoactive intestinal polypeptide-positive interneurons innervating the stratum oriens/alveus border in the CA1 region were shown to establish multiple contacts with horizontal GABAergic interneurons immunoreactive for type 1 metabotropic glutamate receptor. Similarly, identified axons of vasoactive intestinal polypeptide-positive interneurons projecting to stratum radiatum were found to establish symmetrical synapses largely on GABAergic dendrites. The majority of these postsynaptic GABAergic neurons were shown to contain calbindin or vasoactive intestinal polypeptide. In contrast to the first two vasoactive intestinal polypeptide-containing cell populations, vasoactive intestinal polypeptide-positive interneurons arborizing in stratum pyramidale formed baskets around pyramidal cells. These results revealed a new element in cortical microcircuits, interneurons which are specialized to innervate other GABAergic interneurons. The role of this new component may be the synchronization of dendritic inhibition, or an input-specific disinhibition of pyramidal cells in various dendritic domains. In contrast, vasoactive intestinal polypeptide-containing basket cells are likely to be involved in perisomatic inhibition of pyramidal neurons, and represents a new basket cell type different from that containing parvalbumin.

  12. Artificial antifreeze polypeptides: alpha-helical peptides with KAAK motifs have antifreeze and ice crystal morphology modifying properties.

    PubMed

    Zhang, W; Laursen, R A

    1999-07-23

    Antifreeze polypeptides from fish are generally thought to inhibit ice crystal growth by specific adsorption onto ice surfaces and preventing addition of water molecules to the ice lattice. Recent studies have suggested that this adsorption results from hydrogen bonding through the side chains of polar amino acids as well as hydrophobic interactions between the non-polar domains on the ice-binding side of antifreeze polypeptides and the clathrate-like surfaces of ice. In order to better understand the activity of one of the antifreeze polypeptide families, namely the alpha-helical type I antifreeze polypeptides, four alpha-helical peptides having sequences not directly analogous to those of known antifreeze polypeptides and containing only positively charged and non-polar side chains were synthesized. Two peptides with regularly spaced lysine residues, GAAKAAKAAAAAAAKAAKAAAAAAAKAAKAAGGY-NH2 and GAALKAAKAAAAAALKAAKAAAAAALKAAKAAGGY-NH2, showed antifreeze activity, albeit weaker than seen in natural antifreeze polypeptides, by the criteria of freezing point depression (thermal hysteresis) and ice crystal modification to a hexagonal trapezohedron. Peptides with irregular spacing of Lys residues were completely inactive. Up to now, lysine residues have not been generally associated with antifreeze activity, though they have been implicated in some antifreeze polypeptides. This work also shows that lysine residues in themselves, when properly positioned on an alpha-helical polyalanine scaffold, have all the requisite properties needed for such an activity.

  13. Osmotic control of bilayer fusion.

    PubMed Central

    Fisher, L R; Parker, N S

    1984-01-01

    We have used photography and capacitance measurement to monitor the steps in the interaction and eventual fusion of optically black lipid bilayers (BLMs), hydrostatically bulged to approximately hemispherical shape and pushed together mechanically. A necessary first step is drainage of aqueous solution from between the bilayers to allow close contact of the bilayers. The drainage can be controlled by varying the osmotic difference across the bilayers. If the differences are such as to remove water from between the bilayers, fusion occurs after a time that depends on the net osmotic difference and the area of contact. If there is an osmotic flow of water into the space between the bilayers, fusion never occurs. In the fusion process, a single central bilayer forms from the original apposed pair of bilayers. The central bilayer may later burst to allow mixing of the two volumes originally bounded by the separate bilayer; the topological equivalent of exocytosis. Images FIGURE 2 PMID:6541065

  14. Overview of fusion reactor safety

    SciTech Connect

    Cohen, S.; Crocker, J.G.

    1981-01-01

    Use of deuterium-tritium burning fusion reactors requires examination of several major safety and environmental issues: (1) tritium inventory control, (2) neutron activation of structural materials, fluid streams and reactor hall environment, (3) release of radioactivity from energy sources including lithium spill reactions, superconducting magnet stored energy release, and plasma disruptions, (4) high magnetic and electromagnetic fields associated with fusion reactor superconducting magnets and radio frequency heating devices, and (5) handling and disposal of radioactive waste. Early recognition of potential safety problems with fusion reactors provides the opportunity for improvement in design and materials to eliminate or greatly reduce these problems. With an early start in this endeavor, fusion should be among the lower risk technologies for generation of commercial electrical power.

  15. Pulsed Power Driven Fusion Energy

    SciTech Connect

    SLUTZ,STEPHEN A.

    1999-11-22

    Pulsed power is a robust and inexpensive technology for obtaining high powers. Considerable progress has been made on developing light ion beams as a means of transporting this power to inertial fusion capsules. However, further progress is hampered by the lack of an adequate ion source. Alternatively, z-pinches can efficiently convert pulsed power into thermal radiation, which can be used to drive an inertial fusion capsule. However, a z-pinch driven fusion explosion will destroy a portion of the transmission line that delivers the electrical power to the z-pinch. They investigate several options for providing standoff for z-pinch driven fusion. Recyclable Transmission Lines (RTLs) appear to be the most promising approach.

  16. World progress toward fusion energy

    NASA Astrophysics Data System (ADS)

    Clarke, J. F.

    1989-09-01

    This paper will describe the progress in fusion science and technology from a world perspective. The paper will cover the current technical status, including the understanding of fusion's economic, environmental, and safety characteristics. Fusion experiments are approaching the energy breakeven condition. An energy gain (Q) of 30 percent has been achieved in magnetic confinement experiments. In addition, temperatures required for an ignited plasma (Ti = 32 KeV) and energy confinements (about 75 percent of that required for ignition) have been achieved in separate experiments. Two major facilities have started the experimental campaign to extend these results and achieve or exceed Q = 1 plasma conditions by 1990. Inertial confinement fusion experiments are also approaching thermonuclear conditions and have achieved a compression factor 100-200 times liquid D-T. Because of this progress, the emphasis in fusion research is turning toward questions of engineering feasibility. Leaders of the major fusion R and D programs in the European Community (EC), Japan, the United States, and the U.S.S.R. have agreed on the major steps that are needed to reach the point at which a practical fusion system can be designed. The United States is preparing for an experiment to address the last unexplored scientific issue, the physics of an ignited plasma, during the late 1990's. The EC, Japan, U.S.S.R., and the United States have joined together under the auspices of the International Atomic Energy Agency (IAEA) to jointly design and prepare the validating R&D for an international facility, the International Thermonuclear Experimental Reactor (ITER), to address all the remaining scientific issues and to explore the engineering technology of fusion around the turn of the century.

  17. Magnetic fusion 1985: what next

    SciTech Connect

    Fowler, T.K.

    1985-03-01

    Recent budget reductions for magnetic fusion have led to a re-examination of program schedules and objectives. Faced with delays and postponement of major facilities as previously planned, some have called for a near-term focus on science, others have stressed technology. This talk will suggest a different focus as the keynote for this conference, namely, the applications of fusion. There is no doubt that plasma science is by now mature and fusion technology is at the forefront. This has and will continue to benefit many fields of endeavor, both in actual new discoveries and techniques and in attracting and training scientists and engineers who move on to make significant contributions in science, defense and industry. Nonetheless, however superb the science or how challenging the technology, these are means, not ends. To maintain its support, the magnetic fusion program must also offer the promise of power reactors that could be competitive in the future. At this conference, several new reactor designs will be described that claim to be smaller and economically competitive with fission reactors while retaining the environmental and safety characteristics that are the hallmark of fusion. The American Nuclear Society is an appropriate forum in which to examine these new designs critically, and to stimulate better ideas and improvements. As a preview, this talk will include brief discussions of new tokamak, tandem mirror and reversed field pinch reactor designs to be presented in later sessions. Finally, as a preview of the session on fusion breeders, the talk will explore once again the economic implications of a new nuclear age, beginning with improved fission reactors fueled by fusion breeders, then ultimately evolving to reactors based solely on fusion.

  18. Bioresorbable polypeptide-based comb-polymers efficiently improves the stability and pharmacokinetics of proteins in vivo.

    PubMed

    Turabee, Md Hasan; Thambi, Thavasyappan; Lym, Jae Seung; Lee, Doo Sung

    2017-03-13

    Stimuli-responsive polypeptides are a promising class of biomaterials due to their tunable physicochemical and biological properties. Herein, a series of novel pH- and thermo-responsive block copolymers based on polypeptides were synthesized by ring-opening polymerization of γ-benzyl-l-glutamate-N-carboxyanhydride in the presence of poly(ethylene glycol)-diamine macroinitiator followed by aminolysis. The resulting polypeptide-based triblock copolymer, poly[(2-(dibutylamino)ethyl-l-glutamate)-co-(γ-benzyl-l-glutamate)]-poly(ethylene glycol)-b-poly[(2-(dibutylamino)ethyl-l-glutamate)-co-(γ-benzyl-l-glutamate)] (PNLG-co-PBLG-b-PEG-b-PBLG-co-PNLG), exists as a low viscous sol at low pH and temperature (≤pH 6.4, 25 °C) but it transforms to a soft gel under physiological conditions (pH 7.4 and 37 °C). The physical properties of the polypeptide gel can be tuned by controlling the ratio between hydrophobic PBLG and pH-sensitive PNLG blocks. The polypeptide-based copolymer did not show any noticeable cytotoxicity to fibroblast cells in vitro. It was found that subcutaneous injection of the polypeptide copolymer solution into the dorsal region of Sprague-Dawley (SD) rats formed a gel instantly without major inflammation. The gels were completely biodegraded in six weeks and found to be bioresorbable. Human growth hormone (hGH)-loaded polypeptide-based biodegradable copolymer sols readily formed a viscoelastic gel that inhibited an initial burst and prolonged the hGH release for one week. Overall, due to their bioresorbable and sustained release protein characteristics, polypeptide hydrogels may serve as viable platforms for therapeutic protein delivery and the surface tunable properties of polypeptide hydrogels can be exploited for other potential therapeutic proteins.

  19. Horizontal model fusion paradigm

    NASA Astrophysics Data System (ADS)

    Julier, Simon J.; Durrant-Whyte, Hugh F.

    1996-05-01

    In navigation and tracking problems, the identification of an appropriate model of vehicular or target motion is vital to most practical data fusion algorithms. The true system dynamics are rarely known, and approximations are usually employed. Since systems can exhibit strikingly different behaviors, multiple models may be needed to describe each of these behaviors. Current methods either use model switching (a single process model is chosen from the set using a decision rule) or consider the models as a set of competing hypothesis, only one of which is 'correct'. However, these methods fail to exploit the fact that all models are of the same system and that all of them are, to some degree, 'correct'. In this paper we present a new paradigm for fusing information from a set of multiple process models. The predictions from each process model are regarded as observations which are corrupted by correlated noise. By employing the standard Kalman filter equations we combine data from multiple sensors and multiple process models optimally. There are a number of significant practical advantages to this technique. First, the performance of the system always equals or betters that of the best estimator in the set of models being used. Second, the same decision theoretic machinery can be used to select the process models as well as the sensor suites.

  20. Cold fusion verification

    NASA Astrophysics Data System (ADS)

    North, M. H.; Mastny, G. F.; Wesley, E. J.

    1991-03-01

    The objective of this work to verify and reproduce experimental observations of Cold Nuclear Fusion (CNF), as originally reported in 1989. The method was to start with the original report and add such additional information as became available to build a set of operational electrolytic CNF cells. Verification was to be achieved by first observing cells for neutron production, and for those cells that demonstrated a nuclear effect, careful calorimetric measurements were planned. The authors concluded, after laboratory experience, reading published work, talking with others in the field, and attending conferences, that CNF probably is chimera and will go the way of N-rays and polywater. The neutron detector used for these tests was a completely packaged unit built into a metal suitcase that afforded electrostatic shielding for the detectors and self-contained electronics. It was battery-powered, although it was on charge for most of the long tests. The sensor element consists of He detectors arranged in three independent layers in a solid moderating block. The count from each of the three layers as well as the sum of all the detectors were brought out and recorded separately. The neutron measurements were made with both the neutron detector and the sample tested in a cave made of thick moderating material that surrounded the two units on the sides and bottom.

  1. Prospects for Tokamak Fusion Reactors

    SciTech Connect

    Sheffield, J.; Galambos, J.

    1995-04-01

    This paper first reviews briefly the status and plans for research in magnetic fusion energy and discusses the prospects for the tokamak magnetic configuration to be the basis for a fusion power plant. Good progress has been made in achieving fusion reactor-level, deuterium-tritium (D-T) plasmas with the production of significant fusion power in the Joint European Torus (up to 2 MW) and the Tokamak Fusion Test Reactor (up to 10 MW) tokamaks. Advances on the technologies of heating, fueling, diagnostics, and materials supported these achievements. The successes have led to the initiation of the design phases of two tokamaks, the International Thermonuclear Experimental Reactor (ITER) and the US Toroidal Physics Experiment (TPX). ITER will demonstrate the controlled ignition and extended bum of D-T plasmas with steady state as an ultimate goal. ITER will further demonstrate technologies essential to a power plant in an integrated system and perform integrated testing of the high heat flux and nuclear components required to use fusion energy for practical purposes. TPX will complement ITER by testing advanced modes of steady-state plasma operation that, coupled with the developments in ITER, will lead to an optimized demonstration power plant.

  2. Tritium accountancy in fusion systems

    SciTech Connect

    Klein, J.E.; Clark, E.A.; Harvel, C.D.; Farmer, D.A.; Tovo, L.L.; Poore, A.S.; Moore, M.L.

    2015-03-15

    The US Department of Energy (DOE) has clearly defined requirements for nuclear material control and accountability (MCA) of tritium whereas the International Atomic Energy Agency (IAEA) does not since tritium is not a fissile material. MCA requirements are expected for tritium fusion machines and will be dictated by the host country or regulatory body where the machine is operated. Material Balance Areas (MBA) are defined to aid in the tracking and reporting of nuclear material movements and inventories. Material sub-accounts (MSA) are established along with key measurement points (KMP) to further subdivide a MBA to localize and minimize uncertainties in the inventory difference (ID) calculations for tritium accountancy. Fusion systems try to minimize tritium inventory which may require continuous movement of material through the MSA. The ability of making meaningful measurements of these material transfers is described in terms of establishing the MSA structure to perform and reconcile ID calculations. For fusion machines, changes to the traditional ID equation will be discussed which includes breeding, burn-up, and retention of tritium in the fusion device. The concept of 'net' tritium quantities consumed or lost in fusion devices is described in terms of inventory taking strategies and how it is used to track the accumulation of tritium in components or fusion machines. (authors)

  3. TRITIUM ACCOUNTANCY IN FUSION SYSTEMS

    SciTech Connect

    Klein, J. E.; Farmer, D. A.; Moore, M. L.; Tovo, L. L.; Poore, A. S.; Clark, E. A.; Harvel, C. D.

    2014-03-06

    The US Department of Energy (DOE) has clearly defined requirements for nuclear material control and accountability (MC&A) of tritium whereas the International Atomic Energy Agency (IAEA) does not since tritium is not a fissile material. MC&A requirements are expected for tritium fusion machines and will be dictated by the host country or regulatory body where the machine is operated. Material Balance Areas (MBAs) are defined to aid in the tracking and reporting of nuclear material movements and inventories. Material subaccounts (MSAs) are established along with key measurement points (KMPs) to further subdivide a MBA to localize and minimize uncertainties in the inventory difference (ID) calculations for tritium accountancy. Fusion systems try to minimize tritium inventory which may require continuous movement of material through the MSAs. The ability of making meaningful measurements of these material transfers is described in terms of establishing the MSA structure to perform and reconcile ID calculations. For fusion machines, changes to the traditional ID equation will be discussed which includes breading, burn-up, and retention of tritium in the fusion device. The concept of “net” tritium quantities consumed or lost in fusion devices is described in terms of inventory taking strategies and how it is used to track the accumulation of tritium in components or fusion machines.

  4. Effect of polypeptides from sea anemone Heteractis crispa on the rodent blood pressure, heart rate, and hemostasis.

    PubMed

    Skobtsova, L A; Dyachenko, I A; Andreev, Ya A; Logashina, Yu A; Murashev, A N; Grishin, E V

    2016-09-01

    АРНС1-3 peptides, modulators of TRPV1 receptors, have been administered to SD rats to study their influence on the animal hemostatic system, heart rate, and blood pressure. None of АЗРС1-3 polypeptides have any effect on the hemostatic system. Both АРНС1 and АРНС2 polypeptides increased significantly the heart rate, but they did not affect blood pressure, which was probably caused by an ability of these polypeptides to modify animal thermoregulation.

  5. The vasorelaxant effect of pituitary adenylate cyclase activating polypeptide and vasoactive intestinal polypeptide in isolated rat basilar arteries is partially mediated by activation of nitrergic neurons.

    PubMed

    Seebeck, Jörg; Löwe, Marcus; Kruse, Marie Luise; Schmidt, Wolfgang E; Mehdorn, H Maximilian; Ziegler, Albrecht; Hempelmann, Ralf G

    2002-07-15

    The structurally related neuropeptides pituitary adenylate cyclase activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) are recognised by two G protein-coupled receptors, termed VPAC(1)-R and VPAC(2)-R, with equal affinity. PACAP and VIP have previously been shown to relax cerebral arteries in an endothelium-independent manner. The aim of the present study was to test if intramural neurons are involved in the mediation of PACAP/VIP-induced vasodilatory responses. Therefore, the vascular tone of isolated rat basilar arteries was measured by means of a myograph. The vasorelaxing effect of PACAP was assessed in arteries precontracted by serotonin in the absence or presence of different test compounds known to selectively inhibit certain signaling proteins. The vasorelaxant effect of PACAP could be significantly reduced by the inhibitor of neuronal N-type calcium channels omega-conotoxin GVIA (omega-CgTx), as well as by 3-bromo-7-nitroindazole (3Br-7-Ni), an inhibitor of the neuronal nitric oxide-synthase (nNOS). The localization of N-type calcium channels and VPAC-Rs within the rat basilar artery was investigated by confocal laser scanning microscopy using omega-CgTx- and VIP-analogs labelled with fluorescent dyes. These findings suggest that activation of intramural neurons may represent an important effector mechanism for mediation of the vasorelaxant PACAP-response.

  6. Effects of pituitary adenylate cyclase activating polypeptide-27 (PACAP) and vasoactive intestinal polypeptide (VIP) on chloride in HT29 cells studied by X-ray microanalysis.

    PubMed

    Zhang, W; Roomans, G M

    1999-01-01

    The colon cancer cell line HT29 is a useful model to study intestinal chloride secretion. These cells have both cAMP-activated and calcium-activated chloride channels. Changes in elemental content of the cells after stimulation with agonists were determined by X-ray microanalysis in the scanning or scanning transmission electron microscope. Exposure of HT29 cells to pituitary adenylate cyclase activating polypeptide-27 (PACAP) caused a transient decrease in the cellular Cl and K concentrations, indicating (net) efflux of chloride. The effect of PACAP is inhibited by somatostatin, which is known to inhibit cAMP-activated as well as calcium-activated chloride secretion and by U-73122, an inhibitor of phospholipase C. Alloxan, an inhibitor of adenylate cyclase, did not significantly affect the PACAP-induced loss of chloride. The calcium-chelating agent EGTA inhibited the PACAP-induced loss of chloride, indicating the need for extracellular calcium ions. Also vasointestinal polypeptide (VIP) caused a decrease of the cellular chloride concentration in HT29 cells. VIP-induced loss of chloride could be inhibited by pre-treating the cells with somatostatin or UK14,304, an alpha-2 adrenergic agonist that has been shown previously to inhibit purinergically activated chloride efflux. Our results indicate that there is cross-talk between the cAMP- and the calcium-activated pathways for chloride secretion in HT29 cells.

  7. Successful anterior fusion following posterior cervical fusion for revision of anterior cervical discectomy and fusion pseudarthrosis.

    PubMed

    Elder, Benjamin D; Sankey, Eric W; Theodros, Debebe; Bydon, Mohamad; Goodwin, C Rory; Lo, Sheng-Fu; Kosztowski, Thomas A; Belzberg, Allen J; Wolinsky, Jean-Paul; Sciubba, Daniel M; Gokaslan, Ziya L; Bydon, Ali; Witham, Timothy F

    2016-02-01

    Pseudarthrosis occurs after approximately 2-20% of anterior cervical discectomy and fusion (ACDF) procedures; it is unclear if posterior or anterior revision should be pursued. In this study, we retrospectively evaluate the outcomes in 22 patients with pseudarthrosis following ACDF and revision via posterior cervical fusion (PCF). Baseline demographics, preoperative symptoms, operative data, time to fusion failure, symptoms of pseudarthrosis, and revision method were assessed. Fusion outcome and clinical outcome were determined at last follow-up (LFU). Thirteen females (59%) and 9 (41%) males experienced pseudarthrosis at a median of 11 (range: 3-151)months after ACDF. Median age at index surgery was 51 (range: 33-67)years. All patients with pseudarthrosis presented with progressive neck pain, with median visual analog scale (VAS) score of 8 (range: 0-10), and/or myeloradiculopathy. Patients with pseudarthrosis <12 months compared to >12 months after index surgery were older (p=0.013), had more frequent preoperative neurological deficits (p=0.064), and lower baseline VAS scores (p=0.006). Fusion was successful after PCF in all patients, with median time to fusion of 10 (range: 2-14)months. Eighteen patients fused both anteriorly and posteriorly, two patients fused anteriorly only, and two patients fused posteriorly only. Median VAS neck score at LFU significantly improved from the time of pseudarthrosis (p=0.012). While uncommon, pseudarthrosis may occur after ACDF. All patients achieved successful fusion after subsequent posterior cervical fusion, with 91% fusing a previous anterior pseudarthrosis after posterior stabilization. Neck pain significantly improved by LFU in the majority of patients in this study.

  8. Conserved motifs in prokaryotic and eukaryotic polypeptide release factors: tRNA-protein mimicry hypothesis.

    PubMed Central

    Ito, K; Ebihara, K; Uno, M; Nakamura, Y

    1996-01-01

    Translation termination requires two codon-specific polypeptide release factors in prokaryotes and one omnipotent factor in eukaryotes. Sequences of 17 different polypeptide release factors from prokaryotes and eukaryotes were compared. The prokaryotic release factors share residues split into seven motifs. Conservation of many discrete, perhaps critical, amino acids is observed in eukaryotic release factors, as well as in the C-terminal portion of elongation factor (EF) G. Given that the C-terminal domains of EF-G interacts with ribosomes by mimicry of a tRNA structure, the pattern of conservation of residues in release factors may reflect requirements for a tRNA-mimicry for binding to the A site of the ribosome. This mimicry would explain why release factors recognize stop codons and suggests that all prokaryotic and eukaryotic release factors evolved from the progenitor of EF-G. Images Fig. 2 Fig. 3 PMID:8643594

  9. A model for the enantiomeric enrichment of polypeptides on the primitive earth

    NASA Technical Reports Server (NTRS)

    Blair, N. E.; Bonner, W. A.

    1981-01-01

    A potential model is presented for the origin of optical activity in polypeptides on the primitive earth due to enantiomeric enrichment in succeeding polymerization-hydrolysis cycles. The model was developed in experiments with the polymerization of a DL-leucine N-carboxyanhydride mixture with a 31.2% enantiomeric excess of the L isomer with sodium methoxide initiator to yield a polyleucine product which was in turn partially hydrolyzed by acid. The polymerization-hydrolysis was found to produce a net 23.8% increase in the enantiomeric excess of the remaining unhydrolyzed polypeptide (14.2% from the polymerization and 9.6% from the partial hydrolysis). On the basis of these results, it is suggested that a slight excess produced by an appropriate chiral physical process may be enhanced by cycles of stereoselective polymerization and hydrolysis driven by fluctuating wet and dry environmental cycles on the primitive earth.

  10. Membrane-associated polypeptides induced in Chlamydomonas by limiting CO sub 2 concentrations

    SciTech Connect

    Spalding, M.H.; Jeffrey, M. )

    1989-01-01

    Chlamydomonas reinhardtii and other unicellular green algae have a high apparent affinity for CO{sub 2}, little O{sub 2} inhibition of photosynthesis, and reduced photorespiration. These characteristics result from operation of a CO{sub 2}-concentrating system. The CO{sub 2}-concentrating system involves active inorganic carbon transport and is under environmental control. Cells grown at limiting CO{sub 2} concentrations have inorganic carbon transport activity, but cells grown at 5% CO{sub 2} do not. Four membrane-associated polypeptides (M{sub r}, 19, 21, 35, and 36 kilodaltons) have been identified which either appear or increase in abundance during adaptation to limiting CO{sub 2} concentrations. The appearance of two of the polypeptides occurs over roughly the same time course as the appearance of the CO{sub 2}-concentrating system activity in response to CO{sub 2} limitation.

  11. Hierarchical Bionanotubes Formed By the Self Assembly of Microtubules With Cationic Membranes Or Polypeptides

    SciTech Connect

    Raviv, U.; Needleman, D.J.; Ewert, K.K.; Safinya, C.R.

    2009-06-05

    At present there is a surge in interest in biophysical research aimed at elucidating collective interactions between cellular proteins and associated biomolecules leading to supramolecular structures, with the ultimate goal of relating structure to function. The nerve cell cytoskeleton provides a rich example of highly ordered bundles and networks of interacting neurofilaments, microtubules and filamentous actin, where the nature of the interactions, structures and structure-function correlations remain poorly understood. We present synchrotron X-ray diffraction and electron microscopy data, in reconstituted protein systems from the bovine central nervous system, which reveal unexpected structures not predicted by current electrostatic theories. By mixing preassembled microtubules with charged membranes or polypeptides we found hierarchical bionanotubes made of microtubules coated by lipid bilayers or polypeptides, which in turn are coated with a third layer of tubulin oligomers forming rings or spirals.

  12. A novel approach for large-scale polypeptide folding based on elastic networks using continuous optimization.

    PubMed

    Rakshit, Sourav; Ananthasuresh, G K

    2010-02-07

    We present a new computationally efficient method for large-scale polypeptide folding using coarse-grained elastic networks and gradient-based continuous optimization techniques. The folding is governed by minimization of energy based on Miyazawa-Jernigan contact potentials. Using this method we are able to substantially reduce the computation time on ordinary desktop computers for simulation of polypeptide folding starting from a fully unfolded state. We compare our results with available native state structures from Protein Data Bank (PDB) for a few de-novo proteins and two natural proteins, Ubiquitin and Lysozyme. Based on our simulations we are able to draw the energy landscape for a small de-novo protein, Chignolin. We also use two well known protein structure prediction software, MODELLER and GROMACS to compare our results. In the end, we show how a modification of normal elastic network model can lead to higher accuracy and lower time required for simulation.

  13. UV Spectrophotometric Method for Estimation of Polypeptide-K in Bulk and Tablet Dosage Forms

    NASA Astrophysics Data System (ADS)

    Kaur, P.; Singh, S. Kumar; Gulati, M.; Vaidya, Y.

    2016-01-01

    An analytical method for estimation of polypeptide-k using UV spectrophotometry has been developed and validated for bulk as well as tablet dosage form. The developed method was validated for linearity, precision, accuracy, specificity, robustness, detection, and quantitation limits. The method has shown good linearity over the range from 100.0 to 300.0 μg/ml with a correlation coefficient of 0.9943. The percentage recovery of 99.88% showed that the method was highly accurate. The precision demonstrated relative standard deviation of less than 2.0%. The LOD and LOQ of the method were found to be 4.4 and 13.33, respectively. The study established that the proposed method is reliable, specific, reproducible, and cost-effective for the determination of polypeptide-k.

  14. Catalytic and reactive polypeptides and methods for their preparation and use

    DOEpatents

    Schultz, Peter

    1994-01-01

    Catalytic and reactive polypeptides include a binding site specific for a reactant or reactive intermediate involved in a chemical reaction of interest. The polypeptides further include at least one active functionality proximate the binding site, where the active functionality is capable of catalyzing or chemically participating in the chemical reaction in such a way that the reaction rate is enhanced. Methods for preparing the catalytic peptides include chemical synthesis, site-directed mutagenesis of antibody and enzyme genes, covalent attachment of the functionalities through particular amino acid side chains, and the like. This invention was made with Government support under Grant Contract No. AI-24695, awarded by the Department of health and Human Services, and under Grant Contract No. N 00014-87-K-0256, awarded by the Office of Naval Research. The Government has certain rights in this invention.

  15. Self-assembling chimeric polypeptide-doxorubicin conjugate nanoparticles that abolish tumours after a single injection

    NASA Astrophysics Data System (ADS)

    Andrew Mackay, J.; Chen, Mingnan; McDaniel, Jonathan R.; Liu, Wenge; Simnick, Andrew J.; Chilkoti, Ashutosh

    2009-12-01

    New strategies to self-assemble biocompatible materials into nanoscale, drug-loaded packages with improved therapeutic efficacy are needed for nanomedicine. To address this need, we developed artificial recombinant chimeric polypeptides (CPs) that spontaneously self-assemble into sub-100-nm-sized, near-monodisperse nanoparticles on conjugation of diverse hydrophobic molecules, including chemotherapeutics. These CPs consist of a biodegradable polypeptide that is attached to a short Cys-rich segment. Covalent modification of the Cys residues with a structurally diverse set of hydrophobic small molecules, including chemotherapeutics, leads to spontaneous formation of nanoparticles over a range of CP compositions and molecular weights. When used to deliver chemotherapeutics to a murine cancer model, CP nanoparticles have a fourfold higher maximum tolerated dose than free drug, and induce nearly complete tumour regression after a single dose. This simple strategy can promote co-assembly of drugs, imaging agents and targeting moieties into multifunctional nanomedicines.

  16. Thermodynamic Approach to Enhanced Dispersion and Physical Properties in a Carbon Nanotube/Polypeptide Nanocomposite

    NASA Technical Reports Server (NTRS)

    Lovell, Conrad S.; Wise, Kristopher E.; Kim, Jae-Woo; Lillehei, Peter T.; Harrison, Joycelyn S.; Park, Cheol

    2009-01-01

    A high molecular weight synthetic polypeptide has been designed which exhibits favorable interactions with single wall carbon nanotubes (SWCNTs). The enthalpic and entropic penalties of mixing between these two molecules are reduced due to the polypeptide's aromatic sidechains and helical secondary structure, respectively. These enhanced interactions result in a well dispersed SWCNT/Poly (L-Leucine-ran-L-Phenylalanine) nanocomposite with enhanced mechanical and electrical properties using only shear mixing and sonication. At 0.5 wt% loading of SWCNT filler, the nanocomposite exhibits simultaneous increases in the Young's modulus, failure strain, and toughness of 8%, 120%, and 144%, respectively. At one kHz, the same nanotube loading level also enhances the dielectric constant from 2.95 to 22.81, while increasing the conductivity by four orders of magnitude.

  17. Novel Hydrophobin Fusion Tags for Plant-Produced Fusion Proteins

    PubMed Central

    Ritala, Anneli; Linder, Markus; Joensuu, Jussi

    2016-01-01

    Hydrophobin fusion technology has been applied in the expression of several recombinant proteins in plants. Until now, the technology has relied exclusively on the Trichoderma reesei hydrophobin HFBI. We screened eight novel hydrophobin tags, T. reesei HFBII, HFBIII, HFBIV, HFBV, HFBVI and Fusarium verticillioides derived HYD3, HYD4 and HYD5, for production of fusion proteins in plants and purification by two-phase separation. To study the properties of the hydrophobins, we used N-terminal and C-terminal GFP as a fusion partner. Transient expression of the hydrophobin fusions in Nicotiana benthamiana revealed large variability in accumulation levels, which was also reflected in formation of protein bodies. In two-phase separations, only HFBII and HFBIV were able to concentrate GFP into the surfactant phase from a plant extract. The separation efficiency of both tags was comparable to HFBI. When the accumulation was tested side by side, HFBII-GFP gave a better yield than HFBI-GFP, while the yield of HFBIV-GFP remained lower. Thus we present here two alternatives for HFBI as functional fusion tags for plant-based protein production and first step purification. PMID:27706254

  18. Fingerprint analysis of anti-tumor active polypeptides from Arca subcrenata by HPLC.

    PubMed

    Ren, Sheng-fang; Song, Li-yan; Yan, Chun-yan; Li, Ting-fei; Zhao, Yu; Yu, Rong-min

    2008-08-01

    RP-HPLC was applied to analyze active polypeptides in Arca subcrenata, and the optimal condition for separation was also set up: temperature: 30 degrees C; wavelength: 280 nm; flow rate: 1.0 ml/min; Solvent A consisted of 80% acetonitrile and 0.1% trifluoroacetic acid (TFA) and solvent B contained 0.1% TFA. In this condition, ten samples' fingerprints were gained, in one of which the genuine fraction exhibited fourteen "common peaks" representing the characteristics of the constituents.

  19. Adhesion polypeptides are useful for the prevention of peritoneal dissemination of gastric cancer.

    PubMed

    Matsuoka, T; Hirakawa, K; Chung, Y S; Yashiro, M; Nishimura, S; Sawada, T; Saiki, I; Sowa, M

    1998-05-01

    We examined the effect of adhesion polypeptides on the adhesion and invasiveness of gastric cancer cell lines. We previously reported the establishment of an extensively peritoneal-seeding cell line, OCUM-2MD3, from a poorly seeding human scirrhous gastric carcinoma cell line, OCUM-2M. Both alpha2beta1 and alpha3beta1 integrin expression was markedly increased on OCUM-2MD3 cells compared with OCUM-2M cells, and the ability of OCUM-2MD3 cells to bind to the extracellular matrix (ECM) was also significantly higher than that of OCUM-2M cells. The adhesion polypeptides, YIGSR and RGD, and two RGD derivatives significantly inhibited the adhesion of OCUM-2MD3 cells to the submesothelial ECM, while not inhibiting the adhesiveness of OCUM-2M cells and two well differentiated human gastric cell lines, MKN-28 and MKN-74. The YIGSR and RGD peptides also significantly inhibited the invasiveness of OCUM-2MD3 cells. The survival of nude mice with peritoneal dissemination given YIGSR sequence intraperitoneally was obviously longer than that of untreated mice. The survival of mice treated with RGD was also improved, and this effect was increased using the RGD derivatives, poly(CEMA-RGDS) and CM-chitin RGDS. These polypeptides appear to block the binding of integrins, which are expressed on OCUM-2MD3 cells, to the submesothelial ECM, and consequently inhibit peritoneal implantation. The peritoneal injection of adhesion polypeptides may be a new therapy against the dissemination of scirrhous gastric cancer, and may be useful for the prevention of dissemination in high-risk patients.

  20. Folding and self-assembly of polypeptides: Dynamics and thermodynamics from molecular simulation

    NASA Astrophysics Data System (ADS)

    Fluitt, Aaron Michael

    Empowered by their exquisite three-dimensional structures, or "folds," proteins carry out biological tasks with high specificity, efficiency, and fidelity. The fold that optimizes biological function represents a stable configuration of the constituent polypeptide molecule(s) under physiological conditions. Proteins and polypeptides are not static, however: battered by thermal motion, they explore a distribution of folds that is determined by the sequence of amino acids, the presence and identity of other molecules, and the thermodynamic conditions. In this dissertation, we apply molecular simulation techniques to the study of two polypeptides that have unusually diffuse distributions of folds under physiological conditions: polyglutamine (polyQ) and islet amyloid polypeptide (IAPP). Neither polyQ nor IAPP adopts a predominant fold in dilute aqueous solution, but at sufficient concentrations, both are prone to self-assemble into stable, periodic, and highly regular aggregate structures known as amyloid. The appearance of amyloid deposits of polyQ in the brain, and of IAPP in the pancreas, are associated with Huntington's disease and type 2 diabetes, respectively. A molecular view of the mechanism(s) by which polyQ and IAPP fold and self-assemble will enhance our understanding of disease pathogenesis, and it has the potential to accelerate the development of therapeutics that target early-stage aggregates. Using molecular simulations with spatial and temporal resolution on the atomic scale, we present analyses of the structural distributions of polyQ and IAPP under various conditions, both in and out of equilibrium. In particular, we examine amyloid fibers of polyQ, the IAPP dimer in solution, and single IAPP fragments at a lipid bilayer. We also benchmark the molecular models, or "force fields," available for such studies, and we introduce a novel simulation algorithm.

  1. Specific photoaffinity labeling of two plasma membrane polypeptides with an azido auxin

    NASA Technical Reports Server (NTRS)

    Hicks, G. R.; Rayle, D. L.; Jones, A. M.; Lomax, T. L.

    1989-01-01

    Plasma membrane vesicles were isolated from zucchini (Cucurbita pepo) hypocotyl tissue by aqueous phase partitioning and assessed for homogeneity by the use of membrane-specific enzyme assays. The highly pure (ca. 95%) plasma membrane vesicles maintained a pH differential across the membrane and accumulated a tritiated azido analogue of 3-indoleacetic acid (IAA), 5-azido-[7-3H]IAA ([3H]N3IAA), in a manner similar to the accumulation of [3H]IAA. The association of the [3H]N3IAA with membrane vesicles was saturable and subject to competition by IAA and auxin analogues. Auxin-binding proteins were photoaffinity labeled by addition of [3H]N3IAA to plasma membrane vesicles prior to exposure to UV light (15 sec; 300 nm) and detected by subsequent NaDodSO4/PAGE and fluorography. When the reaction temperature was lowered to -196 degrees C, high-specific-activity labeling of a 40-kDa and a 42-kDa polypeptide was observed. Triton X-100 (0.1%) increased the specific activity of labeling and reduced the background, which suggests that the labeled polypeptides are intrinsic membrane proteins. The labeled polypeptides are of low abundance, as expected for auxin receptors. Further, the addition of IAA and auxin analogues to the photoaffinity reaction mixture resulted in reduced labeling that was qualitatively similar to their effects on the accumulation of radiolabeled IAA in membrane vesicles. Collectively, these results suggest that the radiolabeled polypeptides are auxin receptors. The covalent nature of the label should facilitate purification and further characterization of the receptors.

  2. Wall-associated kinase-like polypeptide mediates nutritional status perception and response

    DOEpatents

    Yang, Zhenbiao; Karr, Stephen

    2014-02-11

    The disclosure relates to methods for modulating plant growth and organogenesis using dominant-negative receptor-like kinases. The disclosure further provides a method for increasing plant yield relative to corresponding wild type plants comprising modulating the expression in a plant of a nucleic acid encoding a Wall-Associated Kinase-like 14 polypeptide or a homolog thereof, and selecting for plants having increased yield or growth on a nutrient deficient substrate.

  3. Chiral polyamines from reduction of polypeptides: asymmetric pyridoxamine-mediated transaminations.

    PubMed

    Zhou, Wenjun; Yerkes, Nancy; Chruma, Jason J; Liu, Lei; Breslow, Ronald

    2005-03-01

    BH3.THF can reduce polypeptides to polyamines with retention of chirality. The resulting polyamines are intriguing general platforms for asymmetric catalysis, given the diverse structures available and their relative ease of synthesis. We have constructed a number of chiral pyridoxamine catalysts based on reduced peptides. These compounds transaminate alpha-ketoacids with moderate to good enantioselectivity, while their peptidyl counterparts show almost no chiral induction.

  4. Development of Polymeric Films with Piezoelectrical Properties from Polypeptides; Low, Odd Nylons; or Polyureas.

    DTIC Science & Technology

    1987-09-01

    PIEZOELECTRICAL PROPERTIES FROM POLYPETIDES; LOW, ODD NYLONS; OR POLYUREAS James P. English -LEC"r David P. Vanderbilt Gerald W. McNeely FEBo0 8 SOUTHERN...Nylons; or Polyureas English, James P.; Vanderbilt, David P.; McNeely, Gerald W. 13a. TYPE OF REPORT 13b TIME COVERED 14. DATE OF REPORT (Year, Month...reverSe if necessary and identify by block number) FIELD GROUP SUB-GROUP ,Piezoelectricity, polyamides, polypeptides, poly (amino acids), polyureas , nylon

  5. Fusion Plasma Theory project summaries

    SciTech Connect

    Not Available

    1993-10-01

    This Project Summary book is a published compilation consisting of short descriptions of each project supported by the Fusion Plasma Theory and Computing Group of the Advanced Physics and Technology Division of the Department of Energy, Office of Fusion Energy. The summaries contained in this volume were written by the individual contractors with minimal editing by the Office of Fusion Energy. Previous summaries were published in February of 1982 and December of 1987. The Plasma Theory program is responsible for the development of concepts and models that describe and predict the behavior of a magnetically confined plasma. Emphasis is given to the modelling and understanding of the processes controlling transport of energy and particles in a toroidal plasma and supporting the design of the International Thermonuclear Experimental Reactor (ITER). A tokamak transport initiative was begun in 1989 to improve understanding of how energy and particles are lost from the plasma by mechanisms that transport them across field lines. The Plasma Theory program has actively-participated in this initiative. Recently, increased attention has been given to issues of importance to the proposed Tokamak Physics Experiment (TPX). Particular attention has been paid to containment and thermalization of fast alpha particles produced in a burning fusion plasma as well as control of sawteeth, current drive, impurity control, and design of improved auxiliary heating. In addition, general models of plasma behavior are developed from physics features common to different confinement geometries. This work uses both analytical and numerical techniques. The Fusion Theory program supports research projects at US government laboratories, universities and industrial contractors. Its support of theoretical work at universities contributes to the office of Fusion Energy mission of training scientific manpower for the US Fusion Energy Program.

  6. Hydrogen-bond driven loop-closure kinetics in unfolded polypeptide chains

    SciTech Connect

    Daidone, Isabella; Neuweiler, H; Doose, S; Sauer, M; Smith, Jeremy C

    2010-12-01

    Characterization of the length dependence of end-to-end loop-closure kinetics in unfolded polypeptide chains provides an understanding of early steps in protein folding. Here, loop-closure in poly-glycine-serine peptides is investigated by combining single-molecule fluorescence spectroscopy with molecular dynamics simulation. For chains containing more than 10 peptide bonds loop-closing rate constants on the 20-100 nanosecond time range exhibit a power-law length dependence. However, this scaling breaks down for shorter peptides, which exhibit slower kinetics arising from a perturbation induced by the dye reporter system used in the experimental setup. The loop-closure kinetics in the longer peptides is found to be determined by the formation of intra-peptide hydrogen bonds and transient beta-sheet structure, that accelerate the search for contacts among residues distant in sequence relative to the case of a polypeptide chain in which hydrogen bonds cannot form. Hydrogen-bond-driven polypeptide-chain collapse in unfolded peptides under physiological conditions found here is not only consistent with hierarchical models of protein folding, that highlights the importance of secondary structure formation early in the folding process, but is also shown to speed up the search for productive folding events.

  7. Role of polypeptide growth factors in phenotypic transformation of normal rat kidney cells

    SciTech Connect

    van Zoelen, E.J.J.; van Oostwaard, T.M.J.; de Laat, S.W.

    1988-01-05

    A serum-free assay has been established for studying the role of polypeptide growth factors in inducing loss of density-dependent inhibition of growth of normal rat kidney (NRK) cells. The process has been characterized by measuring the time course of (/sup 3/H)thymidine incorporation into confluent, quiescent NRK cultures stimulated by defined polypeptide growth factors, in combination with cell counting studies, increases in DNA content, and cell cycle analysis by means of a fluorescence-activated cell sorter. It is shown that none of the growth factors tested is able to induce loss of density-dependent inhibition of growth by itself, but strong synergism was observed when combinations of growth factors were tested. None of the above factors was found to be essential, however, since any combination of three of the above four growth factors strongly induced the process. Strong parallels were observed between the growth factor requirements for inducing loss of density-dependent inhibition of growth under serum-free conditions and the requirements for induction of anchorage-independent proliferation under growth factor-defined assay conditions. This indicates that most likely the same cellular processes underlie these two aspects of phenotypic transformation, although data indicate that anchorage-independent proliferation may be a more restricted property of phenotypic transformation than loss of density dependence of proliferation. It is concluded that phenotypic transformation of NRK cells does not require specific polypeptide growth factors, but reflects the ability of these cells to respond to multiple growth factors.

  8. Chiral and structural discrimination in binding of polypeptides with condensed nucleic acid structures.

    PubMed

    Reich, Z; Ittah, Y; Weinberger, S; Minsky, A

    1990-04-05

    In biological systems nucleic acids are invariably found in highly compact forms. These rather intricate forms raise questions of basic importance which are related to the various factors involved in the condensation processes, the chemical, physical, and structural features revealed by the packed species, and the effects of the extremely tight packaging upon interactions of the DNA molecules with proteins and drugs. A means for addressing these questions on a molecular level is provided by various procedures known to induce in vitro condensation of DNA molecules into highly compact species which, in turn, may serve as a model for the in vivo physical organization of nucleic acids. A study of the optical properties of the tightly packed DNA molecules indicates that the interactions of these species with polypeptides are characterized by distinct, hitherto unobserved, chiral and structural discrimination. Specifically, the polypeptides found to be selected against are composed of those amino acids that are not normally used in protein biosynthesis, such as D-lysine or ornithine. These findings provide new clues to long debated topics such as the specific universal chirality of amino acids in proteins or the correlation between conformational flexibility of polypeptides and their ability to form stable compact complexes with nucleic acids.

  9. Common spectrum of polypeptides occurs in secretion granule membranes of different exocrine glands

    SciTech Connect

    Cameron, R.S.; Cameron, P.L.; Castle, J.D.

    1986-10-01

    A highly purified membrane preparation from rat parotid secretion granules has been used as a comparative probe to examine the extent of compositional overlap in granule membranes of three other exocrine secretory tissues - pancreatic, lacrimal, and submandibular - from several standpoints. First, indirect immunofluorescent studies using a polyclonal polyspecific anti-parotid granule membrane antiserum has indicated a selective staining of granule membrane profiles in all acinar cells of all tissues. Second, highly purified granule membrane subfractions have been isolated from each exocrine tissue; comparative two-dimensional (isoelectric focusing; SDS) PAGE of radioiodinated granule membranes has identified 10-15 polypeptides of identical pI and apparent molecular mass. These species are likely to be integral membrane components since they are not extracted by either saponin-sodium sulfate or sodium carbonate (pH 11.5) treatments, and they do not have counterparts in the granule content. Finally, the identity among selected parotid and pancreatic radioiodinated granule membrane polypeptides has been documented using two-dimensional peptide mapping of chymotryptic and tryptic digests. These findings clearly indicate that exocrine secretory granules, irrespective of the nature of stored secretion, comprise a type of vesicular carrier with a common (and probably refined) membrane composition. Conceivably, the polypeptides identified carry out general functions related to exocrine secretion.

  10. A novel polypeptide from shark cartilage with potent anti-angiogenic activity.

    PubMed

    Zheng, Lanhong; Ling, Peixue; Wang, Zheng; Niu, Rongli; Hu, Chaoxin; Zhang, Tianmin; Lin, Xiukun

    2007-05-01

    Using guanidine-HCl extraction, acetone precipitation, ultra-filtration and chromatography, a novel polypeptide with potent anti-angiogenic activity was purified from cartilage of the shark, Prionace glauca. N-terminal amino acid sequence analysis and SDS-PAGE revealed that the substance is a novel polypeptide with MW 15500 (PG155). The anti-angiogenic effects of PG155 were evaluated using zebrafish embryos model in vivo. Treatment of the embryos with 20 microg/ml PG155 resulted in a significant reduction in the growth of subintestinal vessels (SIVs). A higher dose resulted in almost complete inhibition of SIV growth, as observed by endogenous alkaline phosphatase (EAP) staining assay. An in vitro transwell experiment revealed that the polypeptide inhibited vascular endothelial growth factor (VEGF) induced migration and tubulogenesis of human umbilical vein endothelial cells (HUVECs). Exposure of HUVECs in 20 microg/ml PG155 significantly decreased the density of migrated cells. Almost complete inhibition of cell migration was found when HUVECs were treated with 40-80 microg/ml PG155. PG155 (20 microg/ml) markedly inhibited the tube formation of HUVECs and a dose-dependent effect was also found when treatment of HUVECs with PG155 at the concentration from 20-160 microg/ml.

  11. Polycarbophil-cysteine conjugates as platforms for oral polypeptide delivery systems.

    PubMed

    Bernkop-Schnürch, A; Thaler, S C

    2000-07-01

    The purpose of the present study was to evaluate the potential of polycarbophil-cysteine conjugates as carrier systems for orally administered peptide and protein drugs. Mediated by a carbodiimide, cysteine was covalently attached to polycarbophil. The properties of resulting conjugates, displaying 35-50 microM thiol groups per gram of polymer, to bind polypeptides and to inhibit pancreatic proteases was evaluated in vitro. Results demonstrated that only some polypeptides are immobilized to the polycarbophil-cysteine conjugate. Due to the covalent attachment of cysteine to polycarbophil, the inhibitory effect of the polymer toward carboxypeptidase A (EC 3.4. 17.1) and carboxypeptidase B (EC 3.4.17.2) could be significantly (p < 0.05) improved. As the zinc binding affinity of polycarbophil could be improved by the covalent attachment of cysteine, the raised inhibitory effect seems to be based on the complexation of this divalent cation from the enzyme structure. Whereas the covalent attachment of cysteine on polycarbophil had no influence on the enzymatic activity of trypsin (EC 3.4.21.4) and elastase (EC 3.4.21. 36), the inhibitory effect of the polymer-cysteine conjugate toward chymotrypsin (EC 3.4.21.1) was significantly (p < 0.05) higher than that of the unmodified polymer. Because of these inhibitory features, polycarbophil-cysteine conjugates seem to be a promising tool in protecting orally administered therapeutic polypeptides, which are not bound to the polymer, from presystemic metabolism in the intestine.

  12. An altered Q sub B polypeptide as the basis for atrazine resistance in photoautotrophic potato cells

    SciTech Connect

    Smeda, R.J.; Hasegawa, P.M.; Weller, S.C. )

    1990-05-01

    A photoautotrophic potato cell line (variant) was isolated and is capable of sustained growth in media containing the herbicide atrazine at concentrations up to 100-fold greater than the lethal concentration (1.0 {mu}M) for the unselected (wild type) cell line. The basis for atrazine resistance could not be identified by differential uptake or metabolism. Photosynthetic electron transport rates for both intact cell and isolated thylakoid membranes from chloroplasts were unaffected in variant cells at atrazine concentrations up to 100-fold greater than for wild type cells. Photoaffinity labeling of isolated thylakoid membranes from both cell lines with {sup 14}C-azidoatrazine revealed an altered Q{sub B} polypeptide in variant cells resulting in low or no affinity for atrazine. A portion of the chloroplast psbA gene, encoding the Q{sub B} polypeptide, was sequenced for both cell lines. The basis for atrazine resistance in variant cells was identified as a single base change resulting in the alteration of serine to threonine at position 264 of the Q{sub B} polypeptide. In addition to atrazine resistance, variant cells exhibit enhanced tolerance to the herbicides DCMU and metribuzin, but greater sensitivity to bentazon. No reductions in variant cell growth and photosynthetic efficiency in the absence of atrazine were observed.

  13. Induction of human gamma interferon by structurally defined polypeptide fragments of group A streptococcal M protein.

    PubMed Central

    Weigent, D A; Beachey, E H; Huff, T; Peterson, J W; Stanton, G J; Baron, S

    1984-01-01

    The presence of interferon (IFN) has been demonstrated previously (i) in fluids obtained from the middle ears of children with Streptococcus pneumoniae infections, (ii) from the serum of mice injected intraperitoneally with either S. pneumoniae or Streptococcus pyogenes, and (iii) from human lymphoid cell cultures treated with a variety of bacteria. In this study, we showed that highly purified peptic extracts of three different serotypes of group A streptococcal M protein (pep M5, pep M6, and pep M24) stimulated human peripheral leukocytes to produce IFN. IFN production was apparent by 10 h and peaked 24 h after exposure. Dose-response experiments indicated that IFN could be detected in cultures treated with concentrations of M protein as low as 6 micrograms/ml, whereas maximum IFN production occurred at a concentration of 200 micrograms/ml. The IFN had antigenic and physicochemical characteristics of IFN-gamma. Preliminary leukocyte fractionation studies revealed that the IFN-producing cell was a nonadherent lymphocyte with receptors for sheep erythrocytes (T cell). Rabbit antisera specific for these structurally defined polypeptide fragments of streptococcal M protein (pep M5, pep M6, and pep M24) blocked IFN induction by each of the polypeptides. The data suggest that the different serotypes of streptococcal M protein may induce IFN by a common structural determinant shared by each of the polypeptide fragments tested. PMID:6418655

  14. Doxorubicin-loaded polypeptide nanorods based on electrostatic interactions for cancer therapy.

    PubMed

    Zhang, Longlong; Zhang, Pei; Zhao, Qingyun; Zhang, Yongchun; Cao, Longqiao; Luan, Yuxia

    2016-02-15

    An amphiphilic anionic polypeptide, methoxypolyethylene glycol-poly (glutamic acid) (mPEG-PGA), was synthesized, characterized and evaluated as a nanocarrier for the cationic anticancer drug doxorubicin hydrochloride (DOX·HCl). The complex self-assembled into nanorods in aqueous solutions via electrostatic interactions and exhibited a superior drug loading content (50.8%) and drug loading efficiency (90.2%). The average major axis of the drug-loaded nanorods was approximately 300nm, as determined by transmission electron microscopy. An in vitro release assay showed that drug-loaded nanorods exhibited pH-sensitivity and sustained release. Haemolysis assays demonstrated that the polypeptide was haemocompatible, and the polypeptide drug carrier significantly reduced the haemolysis ratio of DOX·HCl. The pharmacokinetics study showed that DOX-loaded nanorods significantly prolonged the resident time in blood. An in vitro cytotoxicity study and cellular uptake assays demonstrated that the DOX-loaded nanorods resulted in higher cell proliferation inhibition and a higher level of tumour cell uptake in A549 cells than with free DOX·HCl. The prolonged circulation and enhanced antitumor efficacy of DOX-loaded nanorods shows promise for efficient cancer chemotherapy.

  15. PEG–Polypeptide Block Copolymers as pH-Responsive Endosome-Solubilizing Drug Nanocarriers

    PubMed Central

    2015-01-01

    Herein we report the potential of click chemistry-modified polypeptide-based block copolymers for the facile fabrication of pH-sensitive nanoscale drug delivery systems. PEG–polypeptide copolymers with pendant amine chains were synthesized by combining N-carboxyanhydride-based ring-opening polymerization with post-functionalization using azide–alkyne cycloaddition. The synthesized block copolymers contain a polypeptide block with amine-functional side groups and were found to self-assemble into stable polymersomes and disassemble in a pH-responsive manner under a range of biologically relevant conditions. The self-assembly of these block copolymers yields nanometer-scale vesicular structures that are able to encapsulate hydrophilic cytotoxic agents like doxorubicin at physiological pH but that fall apart spontaneously at endosomal pH levels after cellular uptake. When drug-encapsulated copolymer assemblies were delivered systemically, significant levels of tumor accumulation were achieved, with efficacy against the triple-negative breast cancer cell line, MDA-MB-468, and suppression of tumor growth in an in vivo mouse model. PMID:24813025

  16. Positively charged polypeptide nanogel enhances mucoadhesion and penetrability of 10-hydroxycamptothecin in orthotopic bladder carcinoma.

    PubMed

    Guo, Hui; Xu, Weiguo; Chen, Jinjin; Yan, Lesan; Ding, Jianxun; Hou, Yuchuan; Chen, Xuesi

    2017-01-03

    Bladder cancer (BC) has become a serious public health problem due to its continuously rising incidence, high recurrence rate, and poor quality of life. Intravesical instillation of chemotherapy, one of common and important treatment strategy for BC, is restricted partially due to the short residence time and the low penetration ability of current antineoplastic agent formulations in clinic. Herein, a positively charged disulfide-core-crosslinked polypeptide nanogel of poly(l-lysine)-poly(l-phenylalanine-co-l-cystine) (PLL-P(LP-co-LC)) was synthesized. 10-Hydroxycamptothecin (HCPT) was loaded into the core via a facile diffusion to obtain loading nanogel (i.e., NG/HCPT). The reduction-responsive cationic polypeptide nanogel not only showed a high drug-loading efficiency, a prolonged residence time, and an improved tissue penetration capability, but also demonstrated an ability to accurately and rapidly release HCPT in bladder cancer cells. NG/HCPT exhibited superior cytotoxicity against human T24 bladder cancer cells compared to that of free HCPT in vitro. Moreover, the positively charged loading nanogel exhibited significantly enhanced antitumor efficacy and reduced side effects toward orthotopic bladder cancer model in vivo. Overall, the smart polypeptide nanogel with enhanced residence and permeability provides a promising drug delivery platform for local chemotherapy of BC.

  17. Cotranslational and Posttranslational N-Glycosylation of Polypeptides by Distinct Mammalian OST Isoforms

    PubMed Central

    Ruiz-Canada, Catalina; Kelleher, Daniel J.; Gilmore, Reid

    2010-01-01

    Summary Asparagine-linked glycosylation of polypeptides in the lumen of the endoplasmic reticulum is catalyzed by the hetero-oligomeric oligosaccharyltransferase (OST). OST isoforms with different catalytic subunits (STT3A versus STT3B) and distinct enzymatic properties are coexpressed in mammalian cells. Using siRNA to achieve isoform-specific knockdowns, we show that the OST isoforms cooperate and act sequentially to mediate protein N-glycosylation. The STT3A OST isoform is primarily responsible for cotranslational glycosylation of the nascent polypeptide as it enters the lumen of the endoplasmic reticulum. The STT3B isoform is required for efficient cotranslational glycosylation of an acceptor site adjacent to the N-terminal signal sequence of a secreted protein. Unlike STT3A, STT3B efficiently mediates posttranslational glycosylation of a carboxyl-terminal glycosylation site in an unfolded protein. These distinct and complementary roles for the OST isoforms allow sequential scanning of polypeptides for acceptor sites to insure the maximal efficiency of N-glycosylation. PMID:19167329

  18. pH-Triggered Polypeptides Nanoparticles for Efficient BODIPY Imaging-Guided Near Infrared Photodynamic Therapy.

    PubMed

    Liu, Le; Fu, Liyi; Jing, Titao; Ruan, Zheng; Yan, Lifeng

    2016-04-13

    An efficient pH-responsive multifunctional polypeptide micelle for simultaneous imaging and in vitro photodynamic therapy (PDT) has been prepared. The goal here is to detect and treat cancer cells by near-infrared fluorescence (NIRF) imaging and PDT synchronously. A photosensitizer BODIPY-Br2 with efficient singlet oxygen generation was synthesized at first which owns both seductive abilities in fluorescence emission and reactive oxygen species (ROS) generation under light irradiation. Then, amphiphilic copolymer micelles pH-triggered disassembly were synthesized from N-carboxyanhydride (NCA) monomer via a ring-opening polymerization and click reaction for the loading of BODIPY-Br2 by hydrophobic interaction, and the driving force is the protonation of the diisopropylethylamine groups conjugated to the polypeptide side chains. In vitro tests performed on HepG2 cancer cells confirm that the cell suppression rate was improved by more than 40% in the presence of light in the presence of an extremely low energy density (12 J/cm(2)) with very low concentration of 5.4 μM photosensitizer. At the same time, the internalization of the nanoparticles by cells can also be traced by NIRF imaging, indicating that the NIR nanoparticles presented imaging guided photodynamic therapy properties. It provides the potential of using polypeptide as a biodegradable carrier for NIR image-guided photodynamic therapy.

  19. Multiple site-selective insertions of non-canonical amino acids into sequence-repetitive polypeptides

    PubMed Central

    Wu, I-Lin; Patterson, Melissa A.; Carpenter Desai, Holly E.; Mehl, Ryan A.; Giorgi, Gianluca

    2013-01-01

    A simple and efficient method is described for introduction of non-canonical amino acids at multiple, structurally defined sites within recombinant polypeptide sequences. E. coli MRA30, a bacterial host strain with attenuated activity for release factor 1 (RF1), is assessed for its ability to support the incorporation of a diverse range of non-canonical amino acids in response to multiple encoded amber (TAG) codons within genetic templates derived from superfolder GFP and an elastin-mimetic protein polymer. Suppression efficiency and isolated protein yield were observed to depend on the identity of the orthogonal aminoacyl-tRNA synthetase/tRNACUA pair and the non-canonical amino acid substrate. This approach afforded elastin-mimetic protein polymers containing non-canonical amino acid derivatives at up to twenty-two positions within the repeat sequence with high levels of substitution. The identity and position of the variant residues was confirmed by mass spectrometric analysis of the full-length polypeptides and proteolytic cleavage fragments resulting from thermolysin digestion. The accumulated data suggest that this multi-site suppression approach permits the preparation of protein-based materials in which novel chemical functionality can be introduced at precisely defined positions within the polypeptide sequence. PMID:23625817

  20. Preparation and Antitumor Activity of CS5931, A Novel Polypeptide from Sea Squirt Ciona Savignyi

    PubMed Central

    Chen, Xiaoshuang; Xu, Huanli; Li, Bo; Wang, Feng; Chen, Xiaoliang; Kong, Dexin; Lin, Xiukun

    2016-01-01

    CS5931 is a novel anticancer agent isolated from the sea squirt Ciona savignyi. However, its content in the species is very low, and developing a novel approach for production of the polypeptide is promising. In the present study, we expressed and purified the polypeptide from E. coli, and the fermentation conditions were studied using response surface methodology. The yield of CS5931 was increased from 2.0 to 7.5 mg/L. The denaturing and renaturation conditions were also studied. Using the optimized renaturation condition, the anticancer activity of refolding CS5931 was increased significantly; the value of IC50 was decreased from 23.2 to 11.6 μM. In vivo study using xenograft nude mice bearing HCT116 cancer cells revealed that CS5931 was able to inhibit the growth of tumor significantly. The study provides a useful approach for obtaining enough amount of CS5931 for further study. This study is also important for developing the polypeptide as a novel anticancer agent. PMID:27007382