Show simple item record

dc.contributor.advisorKahne, Daniel
dc.contributor.authorZhang, Ge
dc.date.accessioned2019-05-16T12:41:08Z
dc.date.created2018-11
dc.date.issued2018-09-16
dc.date.submitted2018
dc.identifier.urihttp://nrs.harvard.edu/urn-3:HUL.InstRepos:39947198*
dc.description.abstractGram-negative bacteria are more difficult to kill than Gram-positive bacteria due to the presence of an outer membrane that prevents many antibiotics from reaching their cellular targets. The outer membrane is an asymmetric bilayer with the inner leaflet consisting of phospholipids and the outer leaflet consisting of lipopolysaccharide (LPS). LPS on the cell surface is responsible for creating this permeability barrier, which allows Gram-negative bacteria to become intrinsically insensitive to many antibiotics. Interfering with LPS biogenesis (biosynthesis and transport) has been shown to affect bacterial viability. However, targeting LPS biogenesis remains challenging since many of the components are membrane proteins with hard-to-assay activities. This dissertation utilizes the non-essentiality of this pathway in a Gram-negative pathogen, Acinetobacter baumannii, as the basis to develop a cell-based screen specific to LPS biogenesis. We used this screen to find a small-molecule inhibitor of MsbA, an essential ATP-dependent LPS flippase in the inner membrane, and validated it as an antibacterial target using a combination of genetics, biochemical and cellular assays. The discovery of a MsbA inhibitor further enabled us to study the cellular responses when LPS transport is hampered. The distinct LPS levels caused by MsbA inhibition and inactivation of a late-stage LPS transport step provide insights into an important question: why are certain steps of LPS biogenesis essential in Acinetobacter when the entire pathway can be removed?
dc.description.sponsorshipChemistry and Chemical Biology
dc.format.mimetypeapplication/pdf
dc.language.isoen
dash.licenseLAA
dc.subjectChemistry, General
dc.subjectBiology, Microbiology
dc.titleThe Development of a Cell-Based Screen for Discovering Lipopolysaccharide Biogenesis Inhibitors
dc.typeThesis or Dissertation
dash.depositing.authorZhang, Ge
dc.date.available2019-05-16T12:41:08Z
thesis.degree.date2018
thesis.degree.grantorGraduate School of Arts & Sciences
thesis.degree.levelDoctoral
thesis.degree.nameDoctor of Philosophy
dc.contributor.committeeMemberSchreiber, Stuart L.
dc.contributor.committeeMemberBalskus, Emily P.
dc.type.materialtext
thesis.degree.departmentChemistry and Chemical Biology
dash.identifier.vireohttp://etds.lib.harvard.edu/gsas/admin/view/2487
dc.description.keywordsDrug discovery; LPS biogenesis
dash.author.emailgongtenggege@gmail.com


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record