Albany 2013: Book of Abstracts
June 11-15 2013
©Adenine Press (2012)
Designing Stiff Protein Nanopores for Challenging Tasks in Biosensing
Protein nanopore-based sensing elements represent a pressing need in molecular biomedical diagnosis (Bayley & Cremer, 2001). However, the integration of protein nanopores with other nanofluidic devices is a challenging task. This is especially true if we consider that isolated single proteins are in general fragile and unstable under harsh conditions of detection. Here, I will present a strategy for improving the stability of the open-state current of a redesigned nanopore using ferric hydroxamate uptake component A (FhuA), a beta-barrel membrane protein channel of E. coli (Mohammad, Iyer, Howard, McPike, Borer & Movileanu, 2012). The primary function of FhuA is to facilitate the energy-driven, high-affinity Fe3+ uptake complexed by the siderophore ferrichrome (Pawelek, Croteau, Ng-Thow-Hing, Khursigara, Moiseeva, Allaire & Coulton, 2006). The key ingredient of this strategy was the coupling of direct genetic engineering of FhuA with a fast-dilution refolding approach to obtain an unusually stable protein nanopore under a broad range of experimentation. These advantageous characteristics were recently demonstrated by examining proteolytic activity of an enzyme at a highly acidic pH, a condition at which majority of beta-barrel protein nanopores are normally gated or unfolded. Future membrane protein design work will not only reveal a better understanding of the processes employed in membrane protein folding and stability, but will also serve as a platform for the integration of robust protein components into devices (Astier, Bayley & Howorka, 2005).
Department of Physics, Syracuse University, 201 Physics Bldg, Syracuse, NY 13244-1130