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Studies of proteins involved in environmental responses of Enterococcus faecalis V583.

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  • Additional Information
    • Series Title:
      Philosophiae Doctor (PhD) Thesis 2011:58
    • Author(s):
    • Address:
      Department of Chemistry, Biotechnology and Food Sciences, Norwegian University of Life Sciences, Ås, Norway.
    • Publication Information:
      Norway
    • Abstract:
      Enterococcus faecalis has traditionally been considered a harmless inhabitant of the gastrointestinal tract of mammals. However, in the past decade E. faecalis has become a major cause of infections in hospitalized patients. Due to a dramatic increase in resistance to most antibiotics, treatment of such infections is difficult. E. faecalis V583 was the first clinical vancomycin-resistant isolate reported in the United States, and the sequencing of its genome was completed in 2003. Increased knowledge of enterococci is crucial for successful development of new methods and therapies to combat the infections that they cause. The main objective of the work described in this thesis was to identify and study proteins involved in environmental responses of E. faecalis V583. The first part of the thesis (Papers I and II) describes a proteomics approach, while the second part describes studies of individual proteins that were selected on the basis of their potential roles in host-microbe interactions (Paper III and IV). In Paper I we identified proteins that were differently expressed after exposure of E. faecalis V583 to bile. Bile is a major stress factor that the bacteria have to cope with in order to survive in the intestinal tract. This study was done using two-dimensional gel electrophoresis combined with mass spectrometry-based identification of differentially expressed proteins. Of a total of 500 proteins visualized on the gels, 53 unique proteins were identified as differently expressed and among these; proteins involved in fatty acid and phospholipid metabolism were overrepresented. The study of Paper I also allowed a comparison of proteome data with (previously generated) transcriptome data. In the study described in Paper II, an enzymatic method for "shaving" of intact cells was combined with high resolution mass spectrometry methods to identify proteins located on the surface of E. faecalis V583. Surface proteins are important for communication and interactions both among bacterial cells and between a bacterium and its environment. This approach led to the identification of 69 unique proteins, of which 36 were predicted to have an extracellular localization. Paper III describes an endo-β-N-acetylglucosaminidase (EF2863) that could potentially enable E. faecalis V583 to deglycosylate host glycoproteins. It was shown that the endo-β-N-acetylglucosaminidase, EfEndo18A, hydrolyses glycosidic linkages in glycoproteins that contain N-linked glycans of the high-mannose and hybrid-type. This may be relevant for enterococcal survival and behavior in the host since it is predicted that two-thirds of the eukaryotic proteins are glycoproteins, including several proteins of the immune system. In addition to being involved in nutrient acquisition, enzymes such as EfEndo18A may also have an effect on the host immune system. E. faecalis V583 contains a chitinolytic machinery whose expression is known to be regulated in response to various environmental stimuli, including stress factors that may be encountered in an animal host. Paper IV show that E. faecalis V583 can grow on chitin and chitin-derived sugars and describes an enzymological chacterization of a chitinase (EF0361) and a chitin binding protein (EF0362). The chitinase, EfChil8A, is an endochitinase, whereas the chitin-binding protein, EfCBM33A, cleaves glycosidic bonds via an oxidative mechanism and acts synergistically with the chitinase. An ultra-high resolution crystal structure of EfCBM33A revealed details of a conserved binding surface that contains the metal-binding catalytic center. There are several studies in the literature indicating that the role of CBM33s could be more complex than a simple food scavenging role, and that suggest roles in virulence and interactions with host cells. Taken together, these studies have provided novel insights into some of the proteins that may be involved in behavior and impact of enterococci and in their interactions with a human host.
    • Number of References:
      many ref.
    • Subject Terms:
      Sugar Industry;Human Nutrition
    • Subject Terms:
    • Accession Number:
      bacterium, carbohydrases, carrier proteins, crystal structure, fat metabolism, gall, mannosyl-glycoprotein endo-beta-N-acetylglucosaminidase, membrane proteins
    • CABICODES:
      Prion, Viral, Bacterial and Fungal Pathogens of Humans (VV210) (New March 2000)
      General Molecular Biology (ZZ360) (Discontinued March 2000)
      Biochemistry and Physiology of Microorganisms (ZZ394) (New March 2000)
    • Accession Number:
      1398-61-4; 9001-06-3
    • Publication Information:
      Thesis; ISBN:9788257510213
    • Accession Number:
      20123053621
    • Copyright:
      ©2012 CAB International
  • Citations
    • ABNT:
      BØHLE, L. B. A. A. Studies of proteins involved in environmental responses of Enterococcus faecalis V583. 2011. Agricultural University of Norway, Department of Chemistry, Biotechnology and Food Science, Ås; Norway, 2011. Disponível em: http://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=lhh&AN=20123053621. Acesso em: 9 abr. 2020.
    • AMA:
      Bøhle LBAA. Studies of proteins involved in environmental responses of Enterococcus faecalis V583. Studies of proteins involved in environmental responses of Enterococcus faecalis V583. 2011:ix + 57. http://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=lhh&AN=20123053621. Accessed April 9, 2020.
    • APA:
      Bøhle, L. B. A. A. (2011). Studies of proteins involved in environmental responses of Enterococcus faecalis V583 [Agricultural University of Norway, Department of Chemistry, Biotechnology and Food Science]. In Studies of proteins involved in environmental responses of Enterococcus faecalis V583 (p. ix + 57).
    • Chicago/Turabian: Author-Date:
      Bøhle, L. B. A. A. 2011. “Studies of Proteins Involved in Environmental Responses of Enterococcus Faecalis V583.” Studies of Proteins Involved in Environmental Responses of Enterococcus Faecalis V583. Philosophiae Doctor (PhD) Thesis 2011:58. Ås; Norway: Agricultural University of Norway, Department of Chemistry, Biotechnology and Food Science. http://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=lhh&AN=20123053621.
    • Harvard:
      Bøhle, L. B. A. A. (2011) Studies of proteins involved in environmental responses of Enterococcus faecalis V583, Studies of proteins involved in environmental responses of Enterococcus faecalis V583. Agricultural University of Norway, Department of Chemistry, Biotechnology and Food Science. Available at: http://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=lhh&AN=20123053621 (Accessed: 9 April 2020).
    • Harvard: Australian:
      Bøhle, LBAA 2011, ‘Studies of proteins involved in environmental responses of Enterococcus faecalis V583’, Agricultural University of Norway, Department of Chemistry, Biotechnology and Food Science, Ås; Norway, Studies of proteins involved in environmental responses of Enterococcus faecalis V583, p. ix + 57, viewed 9 April 2020, .
    • MLA:
      Bøhle, L. B. A. A. “Studies of Proteins Involved in Environmental Responses of Enterococcus Faecalis V583.” Studies of Proteins Involved in Environmental Responses of Enterococcus Faecalis V583, Agricultural University of Norway, Department of Chemistry, Biotechnology and Food Science, 2011, p. ix + 57. EBSCOhost, search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=lhh&AN=20123053621.
    • Chicago/Turabian: Humanities:
      Bøhle, L. B. A. A. “Studies of Proteins Involved in Environmental Responses of Enterococcus Faecalis V583.” Studies of Proteins Involved in Environmental Responses of Enterococcus Faecalis V583. Philosophiae Doctor (PhD) Thesis 2011:58. Agricultural University of Norway, Department of Chemistry, Biotechnology and Food Science, 2011. http://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=lhh&AN=20123053621.
    • Vancouver/ICMJE:
      Bøhle LBAA. Studies of proteins involved in environmental responses of Enterococcus faecalis V583 [Internet]. Studies of proteins involved in environmental responses of Enterococcus faecalis V583. [Ås; Norway]: Agricultural University of Norway, Department of Chemistry, Biotechnology and Food Science; 2011 [cited 2020 Apr 9]. p. ix + 57. (Philosophiae Doctor (PhD) Thesis 2011:58). Available from: http://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=lhh&AN=20123053621