Investigating Wild-Type and Mutated LYS in a 2D Model for Use in Drug Delivery

Student: Jess Ray

Degree: M.S., May 2020

Major Professor: Dr. Radwan Al Faouri

Research Area(s):

Nanoscience & Engineering

View Research Quadslide


  • Wild type lysenin channels were investigated under the influence of different multivalent ions.

  • Pore-forming toxins (PFTs) inserted into liposomes could create new opportunities for drug delivery systems.


  • Use the mutated PFTs in experiments to determine the voltage at which they gate and compare it to wild type PFTs.
  • Control the drug release out of the lysenin-liposome drug carriers to enhance drug delivery applications.


  • Use Teflon chambers to create a bilayer lipid membrane (BLM) model.
  • Prepare lipid solution containing cholesterol, sphingomyelin, and asolectin to create a model cell like animal cell membranes.
  • Insert PFT in the BLM to experimentally determine gating voltages (using Axo-Patch).
  • Introduce multivalent ions to observe the ligand – induced gating.

Key Results

  • Wild type lysenin channels gates at roughly 20mV, while the mutated gated at roughly 30-35mV (as the figure on the left shows).
  • Iron divalent cations inhibit the macroscopic current of both wild and mutated lysenin channels at low monovalent ions concentration (as the figure on the right shows).


  • Mutated type lysenin gated at a higher voltage than the wild type lysenin did, due to the mutation. This led to roughly a 10-15 mV higher voltage required to cause gating in the mutated type.
  • The charge of the mutated lysenin was reduced due to mutation. This led to a higher concentration of iron divalent ions being needed for ligand-induced gating, as hypothesized.

Future Work

  • Repeat all experiments with the mutated lysenin.
  • Investigate the effects pH has on gating.