| Popis: |
Lysenin is a 297-residue polypeptide found in the coelomic fluid of the earthworm E. foetida. It exists as a soluble form in an aqueous environment, and self-inserts into sphingomyelin-containing membranes to form a hexameric channel. This protein demonstrates several remarkable phenomena, including voltage and ligand gating and electrical hysteresis. One of the most striking features of lysenin, however, is that we have observed it to exhibit a photoactivity, specifically a non-transient ionic current upon irradiation. This unique behavior will be discussed, with regards to evolutionary purpose and structural incongruity with the already heavily studied bacteriorhodopsin class of proteins. This presentation will focus on preliminary measurements, which have been focused on confirming that the source of the photoactivity is indeed the protein, running an activity spectrum, quantifying the induced potential and investigating the relevant timescale. Recombinant protein photoactivity will also be discussed, as will plans for future investigation and the potential applications of lysenin. |
