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Bi-Stability, Hysteresis, And Memory Of Voltage-Gated Lysenin Channels, Daniel Fologea, Eric Krueger, Yuriy I. Mazur, Christine Stith, Yui Okuyama, Ralph Henry, Greg J. Salamo

Physics Faculty Publications and Presentations

Lysenin, a 297 amino acid pore-forming protein extracted from the coelomic fluid of the earthworm E. foetida, inserts constitutively open large conductance channels in natural and artificial lipid membranes containing sphingomyelin. The inserted channels show voltage regulation and slowly close at positive applied voltages. We report on the consequences of slow voltage-induced gating of lysenin channels inserted into a planar Bilayer Lipid Membrane (BLM), and demonstrate that these pore-forming proteins constitute memory elements that manifest gating bi-stability in response to variable external voltages. The hysteresis in macroscopic currents dynamically changes when the time scale of the voltage variation is …