CHED 346 |
| Conformational rearrangements in Bacillus anthracis Protective Antigen (PA) were monitored using Fluorescence Resonance Energy Transfer (FRET) microscopy. PA oligomerizes to a PA prepore heptamer, which is taken into the cell by endocytosis. The endosomal environment triggers conformational rearrangements in PA to form a pore. One cysteine mutant per domain of PA was created by site directed mutagenesis and tagged with acceptor or donor fluorophores. Ogliomerization of PA mutant pairs was done in vitro. These resulting heptamers were then incubated in CHO-ATR-1 cells and FRET Efficiency was monitored for the PA prepore and PA pore conformations. Through obtained FRET efficiencies we have estimated relative conformational rearrangements between domains of PA prepore to PA pore. Comparison of our FRET data to a recently proposed model of PA pore, based primarily on PA homology with Staphylococcus aureus á-hemolysin, showed significant deviations from this model and will provide a basis for new structural models. |
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Undergraduate Research Poster Session: Analytical Chemistry
11:00 AM-1:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Division of Chemical Education |