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There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
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In addition to its annual lectures, ChBE hosts a weekly seminar throughout the year with invited lecturers who are prominent in their fields. Unless otherwise noted, all seminars are held on Wednesdays in the Molecular Science and Engineering Building ("M" Building) in G011 (Cherry Logan Emerson Lecture Theater) at 4 p.m. Refreshments are served at 3:30 p.m. in the Emerson-Lewis Reception Salon.
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"Engineering the Beta Roll Peptide to Participate in Useful Biomolecular Interactions"
Scott Banta, Associate Professor, Department of Chemical Engineering, Columbia University
Abstract:
For the last several years we have been exploring the beta roll forming repeats-in-toxin (RTX) peptide as a unique scaffold for protein engineering studies as it has the useful feature of being intrinsically disordered in the absence of calcium, and it folds into a well-defined 3-D structure in the presence of calcium.
We have extensively characterized this conformational change using a variety of techniques. We have explored the capping requirements for the scaffold, we have made synthetic peptides with a repeated consensus sequence, and we have concatenated beta rolls together to explore how this impacts the folding of the peptide. We have also immobilized the peptides to explore their functionality when tethered.
Now we have begun to engineer the beta roll peptide for useful functional applications. In the first line of work, we have engineered one face of the beta roll with leucine side chains. This enables the beta roll to dimerize in the presence of calcium and we have shown that this can serve as a stimulus-responsive cross-linking domain for use in protein hydrogel formation. We have also shown that a consensus sequence of beta roll domains reversibly precipitates in response to calcium and we have explored this as a novel protein purification tag that is more useful than the commonly used elastin-like peptide sequences.
Finally, we have been working to engineer beta roll mutants with affinity for different target proteins using a variety of selection techniques. We have already produced a mutant beta roll with calcium-dependent affinity for lysozyme and we are in the process of expanding this approach. The most recent results of these efforts will also be presented.
