Raman Spectroscopy as a Tool for Investigating Lipid-Protein Interactions

A particular area of biophysical research in which Raman spectroscopy has great potential is the study of lipid–protein interactions. It is becoming increasingly clear that lipids can modulate membrane-embedded protein function and vice versa. This modulation can take both specific and nonspecific forms, but the underlying framework is defined by the amphiphatic nature of lipids and proteins. Proteins are embedded in the lipid bilayer by virtue of their hydrophilic and hydrophobic moieties expressed in the notion of hydrophobic coupling. Of special interest is the preferential enrichment of aromatic residues (for example, tryptophan [Trp]) in the interface between the hydrophilic aqueous phases and the hydrophobic bilayer core. The reason for this and its relation to hydrophobic coupling is not clear despite intensive research.