Biophysical studies of bacterial proteins; can we address antibiotic resistance?

Simple item page
atmire.migration.oldid5451
dc.contributor.advisorVogel, Hans
dc.contributor.authorPaul, Subrata
dc.contributor.committeememberRo, Dae-Kyun
dc.contributor.committeememberZaremberg, Vanina
dc.date.accessioned2017-04-27T15:23:31Z
dc.date.available2017-04-27T15:23:31Z
dc.date.issued2017
dc.date.submitted2017en
dc.description.abstractIt is forecast that the single biggest challenge to medical care in the twenty-first century will be the control of antibiotic resistant bacteria, including multidrug resistant strains. Although numerous factors are associated with the rapid emergence of pathogen resistance, the limited number of core structures of currently used antibiotics is one of the reasons for this development. Unlike other conventional antibiotics, the recently discovered class of lipopeptide antibiotics consists of a cyclic peptide head group with an acyl chain that are synthesized by a non-ribosomal peptide synthetase in association with an acyl carrier protein (ACP). This dissertation presents the solution structure of an ACP, LipD that is involved in the acylation of the lipopeptide antibiotic friulimicin. Enhanced stability of holo-LipD (LipD with the phosphopantetheine group attached) was observed through biophysical investigations. This may originate from a subtle change in the helix angles, required for the attachment of the acyl chain. Moreover, interaction studies of ACPs with antimicrobial peptides (AMPs) revealed that bacterial ACPs can be novel targets for AMPs and that this may perturb the fatty acid synthesis to abrogate the pathogenesis of recalcitrant pathogens such as Pseudomonas aeruginosa. We also investigated the ligand binding properties of two selected periplasmic binding proteins (PBP). Understanding the mechanisms by which PBPs can bind and release various ligands has implications for designing biosensors and developing therapeutic compounds that will perturb the pathways mediated by PBPs. Detailed biophysical studies of the Escherichia.coli ferric citrate binding PBP, FecB, revealed that it could form complexes with a wide variety of different tricarboxylic acid-iron complexes. Moreover unexpectedly FecB was found to bind apo-citrate and other iron-free tricarboxylic acids with great avidity. Information regarding the plasticity of substrate binding by FecB will allow us to design new strategies to overcome bacterial resistance. On the other hand, we demonstrated that E. coli HisJ interacts with L-histidine with nM affinity and can also bind 3-methyl-L-histidine, which has been identified as a biomarker for muscle wasting. Therefore, HisJ can potentially be used to design a reagentless protein-based biosensor for the early detection of this muscle disease.en_US
dc.identifier.citationPaul, S. (2017). Biophysical studies of bacterial proteins; can we address antibiotic resistance? (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25138en_US
dc.identifier.doihttp://dx.doi.org/10.11575/PRISM/25138
dc.identifier.urihttp://hdl.handle.net/11023/3749
dc.language.isoeng
dc.publisher.facultyGraduate Studies
dc.publisher.institutionUniversity of Calgaryen
dc.publisher.placeCalgaryen
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subjectBiochemistry
dc.titleBiophysical studies of bacterial proteins; can we address antibiotic resistance?
dc.typedoctoral thesis
thesis.degree.disciplineBiological Sciences
thesis.degree.grantorUniversity of Calgary
thesis.degree.nameDoctor of Philosophy (PhD)
ucalgary.item.requestcopytrue
Files
Collections
Open Theses and Dissertations