Y. Musa, K. Tantawi, M. Colson, A. Adams
Motlow State Community College,
United States
Keywords: lipid bilayer membranes, molecular dynamics simulation, electrochemical impedance spectroscopy
Summary:
In this work we use Molecular Dynamics (MD) simulations to assess the stability of a simplified model of the lipid bilayer membrane (LBM) of chemo-stressed cancer cell under an applied electric field. Researchers commonly use Electrochemical Impedance Spectroscopy (EIS) to study the electrophysiology of LBMs in which the electrical response is collected under an applied electric potential that usually is in the range 100 mV to 1000 mV. The simplified LBM model that was constructed here consists of phospholipids with only the serine headgroup and saturated fatty acid chains, and the LBMs response to an an externally applied electric field was recorded for potentials from 30 mV to 1000 mV for a duration of 100 to 300 picoseconds. 120 molecules per leaflet were used of the phospholipid 1,2-dioctadecanoyl-sn-glycero-3-phosphoserine (DSPS) which has stearic acid tails and the serine headgroup, and with a hydration number of 35 were used to construct the simplified model of the chemo-stressed LBM of a cancer cell. MD simulation shows that the lipid bilayer membrane (LBM) remained intact with almost no observed effect after applying an electric potential of up to 1000 mV across it for the first 100 ps. Formation and recombination of channels that did not connect all the way through and lipid flipping were observed at potentials of 900 mV and 1000 mV starting at about 277 picoseconds.