Impedance Analysis of Lipid Domains in Phosphatidylcholine Bilayer Membranes Containing Ergosterol

Abstract

The effect of ergosterol on the electrochemical features of the phosphatidylcholine bilayer membrane was investigated by impedance spectroscopy. The experimental impedance values obtained in the presence of different amounts of ergosterol showed evidence of domain structures within the bilayer containing < 0.06 molar fraction of ergosterol. Based on derived mathematical equations, the surface area of phospholipid/ergosterol domain was calculated; it amounts to 262 A(2). This value is consistent, taking into consideration the presented measurements as well as ordering and condensation effects of ergosterol, with a stoichiometry of such a domain equal to 3:1. The result of the investigation is the proposal of a new and simple method for the determination of the surface area and description stoichiometry of domains formed in any two-component system.

Pore Formation in Lipid Bilayer Membranes made of Phosphatidylcholine and Cholesterol Followed by Means of Constant Current

“…The value of R m obtained for a PC membrane was 3.64 ± 0.32 × 10 5 Ω cm 2 , and the mean C m value of a PC bilayer was 0.66 ± 0.04 μF cm −2 , similar to values reported in the literature [28, 29]. When a passive RC circuit with electrical parameters corresponding to the typical BLMs formed in our laboratory was analyzed using electrochemical impedance spectroscopy, results similar to those obtained for pure phosphatidylcholine membranes at low current density values (no electroporation) were obtained [17, 30]. Impedance spectroscopy is a noninvasive technique capable of accurately measuring electrical parameters [31–33].…”

Electrochemical Impedance Spectroscopy and its Applications

“…Hydrophobic part Lipid bilayer Interesting studies were performed on membranes composed of two components, where the formation of complexes or domains was possible [510,511,[514][515][516][521][522][523][524][525].…”

Critical Overview of the Use of Tethered Bilayer Lipid Membranes with Electrochemical Techniques

“…Simply using PC head groups and fully saturated lipid tails to build a t-BLM is not an accurate enough biological mimic. Electrochemical Impedance Spectroscopy (EIS) is a common technique used to monitor the conductivity and dielectric properties of t-BLM [26,43,[49][50][51][52]. EIS is the only technique that allows the simultaneous visualisation of conductivity and resistance.…”