The Experts below are selected from a list of 5607 Experts worldwide ranked by ideXlab platform

Daniel J. Rigden - One of the best experts on this subject based on the ideXlab platform.

  • employing in vitro Directed Molecular Evolution for the selection of α amylase variant inhibitors with activity toward cotton boll weevil enzyme
    Journal of Biotechnology, 2013
    Co-Authors: Maria Cristina Mattar Da Silva, Daniel J. Rigden, Erika V.s. Albuquerque, Rafael Perseghini Del Sarto, Wagner Alexandre Lucena, F R Teixeira, Caroline De Andrade Bezerra, Maria Fatima Grossidesa
    Abstract:

    Numerous species of insect pests attack cotton plants, out of which the cotton boll weevil (Anthonomus grandis) is the main insect in Brazil and must be controlled to avert large economic losses. Like other insect pests, A. grandis secretes a high level of α-amylases in the midgut lumen, which are required for digestion of carbohydrates. Thus, α-amylase inhibitors (α-AIs) represent a powerful tool to apply in the control of insect pests. Here, we applied DNA shuffling and phage display techniques and obtained a combinatorial library containing 108α-AI variant forms. From this library, variants were selected exhibiting in vitro affinity for cotton boll weevil α-amylases. Twenty-six variant sequences were cloned into plant expression vectors and expressed in Arabidopsis thaliana. Transformed plant extracts were assayed in vitro to select specific and potent α-amylase inhibitors against boll weevil amylases. While the wild type inhibitors, used to create the shuffled library, did not inhibit the A. grandis α-amylases, three α-AI mutants, named α-AIC3, α-AIA11 and α-AIG4 revealed high inhibitory activities against A. grandis α-amylases in an in vitro assay. In summary, data reported here shown the potential biotechnology of new α-AI variant genes for cotton boll weevil control.

  • Improving Cry8Ka toxin activity towards the cotton boll weevil (Anthonomus grandis).
    BMC biotechnology, 2011
    Co-Authors: G. R. Oliveira, Erich Y. T. Nakasu, Alexandre Augusto Pereira Firmino, Wagner A. Lucena, Maria Cristina Mattar Da Silva, Magda Aparecida Beneventi, Djair S.l. Souza, José E Gomes, José Dijair Antonino De Souza, Daniel J. Rigden
    Abstract:

    Background The cotton boll weevil (Anthonomus grandis) is a serious insect-pest in the Americas, particularly in Brazil. The use of chemical or biological insect control is not effective against the cotton boll weevil because of its endophytic life style. Therefore, the use of biotechnological tools to produce insect-resistant transgenic plants represents an important strategy to reduce the damage to cotton plants caused by the boll weevil. The present study focuses on the identification of novel molecules that show improved toxicity against the cotton boll weevil. In vitro Directed Molecular Evolution through DNA shuffling and phage display screening was applied to enhance the insecticidal activity of variants of the Cry8Ka1 protein of Bacillus thuringiensis.

Barbara E. Power - One of the best experts on this subject based on the ideXlab platform.

  • ribosome display for improved biotherapeutic molecules
    Expert Opinion on Biological Therapy, 2006
    Co-Authors: Achim Rothe, Ralf J. Hosse, Barbara E. Power
    Abstract:

    Ribosome display presents an innovative in vitro technology for the rapid isolation and Evolution of high-affinity peptides or proteins. Displayed proteins are bound to and recovered from target molecules in multiple rounds of selection in order to enrich for specific binding proteins. No transformation step is necessary, which could lead to a loss of library diversity. A cycle of display and selection can be performed in one day, enabling the existing gene repertoire to be rapidly scanned. Proteins isolated from the panning rounds can be further modified through random or Directed Molecular Evolution for affinity maturation, as well as selected for characteristics such as protein stability, folding and functional activity. Recently, the field of display technologies has become more prominent due to the generation of new scaffolds for ribosome display, isolation of high-affinity human antibodies by phage display, and their implementation in the discovery of novel protein–protein interactions. Applications...

G. R. Oliveira - One of the best experts on this subject based on the ideXlab platform.

  • Improving Cry8Ka toxin activity towards the cotton boll weevil (Anthonomus grandis).
    BMC biotechnology, 2011
    Co-Authors: G. R. Oliveira, Erich Y. T. Nakasu, Alexandre Augusto Pereira Firmino, Wagner A. Lucena, Maria Cristina Mattar Da Silva, Magda Aparecida Beneventi, Djair S.l. Souza, José E Gomes, José Dijair Antonino De Souza, Daniel J. Rigden
    Abstract:

    Background The cotton boll weevil (Anthonomus grandis) is a serious insect-pest in the Americas, particularly in Brazil. The use of chemical or biological insect control is not effective against the cotton boll weevil because of its endophytic life style. Therefore, the use of biotechnological tools to produce insect-resistant transgenic plants represents an important strategy to reduce the damage to cotton plants caused by the boll weevil. The present study focuses on the identification of novel molecules that show improved toxicity against the cotton boll weevil. In vitro Directed Molecular Evolution through DNA shuffling and phage display screening was applied to enhance the insecticidal activity of variants of the Cry8Ka1 protein of Bacillus thuringiensis.

Juha Punnonen - One of the best experts on this subject based on the ideXlab platform.

  • dna shuffling and screening strategies for improving vaccine efficacy
    DNA and Cell Biology, 2005
    Co-Authors: Christopher P Locher, Robert G. Whalen, Madan M Paidhungat, Juha Punnonen
    Abstract:

    The efficacy of vaccines can be improved by increasing their immunogenicity, broadening their crossprotective range, as well as by developing immunomodulators that can be coadministered with the vaccine antigen. One technology that can be applied to each of these aspects of vaccine development is MolecularBreeding Directed Molecular Evolution. Essentially, this technology is used to evolve genes in vitro through an iterative process consisting of recombinant generation followed by selection of the desired recombinants. We have used DNA shuffling and screening strategies to develop and improve vaccine candidates against several infectious pathogens including Plasmodium falciparum (a common cause of severe and fatal human malaria), dengue virus, encephalitic alphaviruses such as Venezuelan, western and eastern equine encephalitis viruses (VEEV, WEEV, and EEEV, respectively), human immunodeficiency virus-1 (HIV-1), and hepatitis B virus (HBV). By recombining antigen-encoding genes from different serovar isolates, new chimeras are selected for crossreactivity; these vaccine candidates are expected to provide broader crossprotection than vaccines based on a single serovar. Furthermore, the vaccine candidates can be selected for improved immunogenicity, which would also improve their efficacy. In addition to vaccine candidates, we have applied the technology to evolve several immunomodulators that when coadministered with vaccines can improve vaccine efficacy by fine-tuning the T cell response. Thus, DNA shuffling and screening technology is a promising strategy to facilitate vaccine efficacy.

  • development of novel vaccines using dna shuffling and screening strategies
    Current Opinion in Molecular Therapeutics, 2004
    Co-Authors: Christopher P Locher, Robert G. Whalen, Nay Wei Soong, Juha Punnonen
    Abstract:

    DNA shuffling and screening technologies recombine and evolve genes in vitro to rapidly obtain molecules with improved biological activity and fitness. In this way, genes from related strains are bred like plants or livestock and their successive progeny are selected. These technologies have also been called Molecular breeding-Directed Molecular Evolution. Recent developments in bioinformatics-assisted computer programs have facilitated the design, synthesis and analysis of DNA shuffled libraries of chimeric molecules. New applications in vaccine development are among the key features of DNA shuffling and screening technologies because genes from several strains or antigenic variants of pathogens can be recombined to create novel molecules capable of inducing immune responses that protect against infections by multiple strains of pathogens. In addition, molecules such as co-stimulatory molecules and cytokines have been evolved to have improved T-cell proliferation and cytokine production compared with the wild-type human molecules. These molecules can be used to immunomodulate vaccine responsiveness and have multiple applications in infectious diseases, cancer, allergy and autoimmunity. Moreover, DNA shuffling and screening technologies can facilitate process development of vaccine manufacturing through increased expression of recombinant polypeptides and viruses. Therefore, DNA shuffling and screening technologies can overcome some of the challenges that vaccine development currently faces.

Maria Cristina Mattar Da Silva - One of the best experts on this subject based on the ideXlab platform.

  • employing in vitro Directed Molecular Evolution for the selection of α amylase variant inhibitors with activity toward cotton boll weevil enzyme
    Journal of Biotechnology, 2013
    Co-Authors: Maria Cristina Mattar Da Silva, Daniel J. Rigden, Erika V.s. Albuquerque, Rafael Perseghini Del Sarto, Wagner Alexandre Lucena, F R Teixeira, Caroline De Andrade Bezerra, Maria Fatima Grossidesa
    Abstract:

    Numerous species of insect pests attack cotton plants, out of which the cotton boll weevil (Anthonomus grandis) is the main insect in Brazil and must be controlled to avert large economic losses. Like other insect pests, A. grandis secretes a high level of α-amylases in the midgut lumen, which are required for digestion of carbohydrates. Thus, α-amylase inhibitors (α-AIs) represent a powerful tool to apply in the control of insect pests. Here, we applied DNA shuffling and phage display techniques and obtained a combinatorial library containing 108α-AI variant forms. From this library, variants were selected exhibiting in vitro affinity for cotton boll weevil α-amylases. Twenty-six variant sequences were cloned into plant expression vectors and expressed in Arabidopsis thaliana. Transformed plant extracts were assayed in vitro to select specific and potent α-amylase inhibitors against boll weevil amylases. While the wild type inhibitors, used to create the shuffled library, did not inhibit the A. grandis α-amylases, three α-AI mutants, named α-AIC3, α-AIA11 and α-AIG4 revealed high inhibitory activities against A. grandis α-amylases in an in vitro assay. In summary, data reported here shown the potential biotechnology of new α-AI variant genes for cotton boll weevil control.

  • Improving Cry8Ka toxin activity towards the cotton boll weevil (Anthonomus grandis).
    BMC biotechnology, 2011
    Co-Authors: G. R. Oliveira, Erich Y. T. Nakasu, Alexandre Augusto Pereira Firmino, Wagner A. Lucena, Maria Cristina Mattar Da Silva, Magda Aparecida Beneventi, Djair S.l. Souza, José E Gomes, José Dijair Antonino De Souza, Daniel J. Rigden
    Abstract:

    Background The cotton boll weevil (Anthonomus grandis) is a serious insect-pest in the Americas, particularly in Brazil. The use of chemical or biological insect control is not effective against the cotton boll weevil because of its endophytic life style. Therefore, the use of biotechnological tools to produce insect-resistant transgenic plants represents an important strategy to reduce the damage to cotton plants caused by the boll weevil. The present study focuses on the identification of novel molecules that show improved toxicity against the cotton boll weevil. In vitro Directed Molecular Evolution through DNA shuffling and phage display screening was applied to enhance the insecticidal activity of variants of the Cry8Ka1 protein of Bacillus thuringiensis.