Melting of Single Lipid Components in Binary Lipid Mixtures: A Comparison between FTIR Spectroscopy, DSC and Monte Carlo Simulations

TL;DR

This study combines FTIR spectroscopy, DSC, and Monte Carlo simulations to analyze the melting behavior of individual lipids in binary membranes, providing both microscopic and macroscopic insights into lipid phase transitions.

Contribution

It introduces an integrated approach linking FTIR, DSC, and MC simulations to comprehensively study lipid melting behavior in binary mixtures.

Findings

FTIR reveals microscopic melting details of single lipids.

MC simulations accurately describe microscopic melting behavior.

DSC provides heat capacity and thermodynamic data.

Abstract

Monte Carlo (MC) Simulations, Differential Scanning Calorimetry (DSC) and Fourier Transform InfraRed (FTIR) spectroscopy were used to study the melting behavior of single lipid components in two-component membranes of 1,2-Dimyristoyl-D54-sn-Glycero-3-Phosphocholine (DMPC-d54) and 1,2-Distearoyl-sn-Glycero-3-Phosphocholine (DSPC). Microscopic information on the temperature dependent melting of the single lipid species could be investigated using FTIR. The microscopic behavior measured could be well described by the results from the MC simulations. These simulations also allowed to calculate heat capacity profiles as determined with DSC. These ones provide macroscopic information about melting enthalpies and entropy changes which are not accessible with FTIR. Therefore, the MC simulations allowed us to link the two different experimental approaches of FTIR and DSC.