dc.creator | Mushrush, Darren J | |
dc.date.accessioned | 2020-08-22T20:52:20Z | |
dc.date.available | 2011-09-06 | |
dc.date.issued | 2011-09-06 | |
dc.identifier.uri | https://etd.library.vanderbilt.edu/etd-08252011-124331 | |
dc.identifier.uri | http://hdl.handle.net/1803/14006 | |
dc.description.abstract | Botulinum neurotoxin (BoNT) belongs to a large class of toxic proteins that act by enzymatically modifying cytosolic substrates within eukaryotic cells. The process by which a catalytic moiety is transferred across a membrane to enter the cytosol is not understood for any such toxin. BoNT is known to form pH-dependent pores important for the translocation of the catalytic domain into the cytosol. As a first step toward understanding this process, we have investigated the mechanism by which the translocation domain of BoNT associates with a model liposome membrane. We report conditions that allow pH-dependent proteoliposome formation and identify a sequence at the translocation domain C-terminus that is protected from proteolytic degradation in the context of the proteoliposome. Fluorescence quenching experiments suggest that residues within this sequence move to a hydrophobic environment upon association with liposomes. Electron paramagnetic resonance analyses of spin labeled mutants reveal major conformational changes in a distinct region of the structure upon association and indicate the formation of an oligomeric membrane-associated intermediate. Together, these data support a model of how BoNT orients with membranes in response to low pH. | |
dc.format.mimetype | application/pdf | |
dc.subject | liposomes | |
dc.subject | EPR | |
dc.subject | fluorescence | |
dc.subject | bacterial toxin | |
dc.subject | biophysics | |
dc.title | Mechanistic details of the pH-dependent association of botulinum neurotoxin with membranes | |
dc.type | dissertation | |
dc.contributor.committeeMember | Michael R. Waterman | |
dc.contributor.committeeMember | Richard N. Armstrong | |
dc.contributor.committeeMember | Hassane S. Mchaourab | |
dc.contributor.committeeMember | Charles R. Sanders | |
dc.type.material | text | |
thesis.degree.name | PHD | |
thesis.degree.level | dissertation | |
thesis.degree.discipline | Biochemistry | |
thesis.degree.grantor | Vanderbilt University | |
local.embargo.terms | 2011-09-06 | |
local.embargo.lift | 2011-09-06 | |
dc.contributor.committeeChair | D. Borden Lacy | |