Biophysical Properties of Lysenin Channels

Dr. Daniel Fologea
Department of Physics
Boise State University

Lysenin, a 297 amino acids pore forming protein extracted from the coelomic fluid of the earthworm Eisenia foetida, inserts large conductance channels into artificial and natural lipid membranes containing sphingomyelin. The cytolytic and hemolytic activity of lysenin points out a pore-forming toxin. However, lysenin channels share many of the salient features of ion channels, namely high transport rate, regulation, and selectivity.  This presentation covers fundamental biophysical aspects of the lysenin channel functionality in relation to voltage induced gating, ligand induced gating, slow inactivation, ionic transport,  and macromolecular transport. The single-channel analysis offers a deeper insight into the mechanism of channel gating induced by multivalent cations, and the analysis of temperature-dependent voltage induced gating indicates dynamic changes in the energy landscape as responsible for the intrinsic memory function. The intriguing and intricate features of the lysenin channels open new avenues in developing lysenin-based applications for biosensing, controlled transport, advanced artificial drug delivery systems, and single molecule analysis.