Effect of Gramicidin S on the Dipalmitoylphosphatidyl-glycerol Thermotropic Phase Transition in DPPG/GS Systems: A Mathematical Approach

Abstract

We present a mathematical approach to the experimental data recorded via Fourier transform-infrared spectroscopy regarding the influence of the concentration of the antimicrobial peptide gramicidin S (GS) on the thermotropic phase transition of the dipalmitoylphosphatidyl-glycerol (DPPG) lipid bilayer membrane in DPPG=GS systems. The model is based on the influence of the GS concentration on the parameters of a nonlinear damped oscillator, which models the CH 2 symmetric stretching band.

Temperature Dependence of the Phospholipids Bilayers Stability, Studied by FTIR Spectroscopy

“…Their use eliminates the multitude of factors that influence the biological membrane fluidity, a natural condition for their functionality. The influence of the external electric fields [5,6] of concentration [7,8] or of temperature [9][10][11] on the lyotropic or thermotropic liquid crystals was intensively studied in the past years by electric [5], DSC [12] or spectral means [10,11,[13][14][15], in order to establish the properties of the model membranes.…”