About the seminar:

Lipid bilayers form the basis of the cell membrane, with the hydrophobic bilayer interior acting as the solvent for membrane proteins. These bilayers undergo a temperature-induced phase transition from an ordered phase to a disordered phase which affects membrane protein structure and functionality. Depth-dependent spectroscopic studies can describe these phase transitions. However, common methods either use large probes which can disrupt the bilayer or cannot access fast enough time scales to describe ultrafast molecular processes. Vibrational spectroscopy can overcome both of these limitations. The paper I will discuss (Islam et al., J. Am. Chem. Soc. 2023, 145, 48, 26363–26373) introduces a set of test compounds composed of an azide group bonded to an alkyl chain of varying lengths. The azide vibrational probe sits at specific depths within a model bilayer system depending on the alkyl chain length. This probe allows for FTIR and ultrafast 2D-IR investigations of the lipid bilayer at different depths without disturbing the bilayer interior. The method described in this paper could be used to describe the effects of a phase transition at specific locations on membrane proteins, elucidating biological consequences of phase transitions.