Landscape of Lipid–Protein Interactions

 Lipids and proteins are the two significant molecules present in the cell membrane. The matrix, consisting of a lipid bilayer, is the essential structural element of biological membranes. The protein enables information processing that reaches the cellular membranes and controls the selective transport of materials. Cell membranes regulate the flow of energy, information, nutrients, and metabolites between the cells. It also removes waste materials from cells and transfers nutrients into cells. The surrounding lipid environment's dynamic nature can influence a membrane protein's functionality. The interaction between the membrane lipids and proteins helps maintain membrane geometry; the presence of a lipid-protein complex is the active site for various cellular mechanisms and is the primary target for developing anticancer and antimicrobial drugs. Van der Waals forces, hydrogen bonds, and/or electrostatic interactions are the main sources of weak interactions between annular lipids and proteins. Phosphatidylglycerol and phosphatidylethanolamine interact with a specific type of ABC transporter protein, which is associated with conditions like multidrug resistance. Incorporating GTPase into the bilayer disrupts the lipid arrangement and causes the outer membrane leaflet to elongate; the disruption and elongation of the membrane cause the endoplasmic reticulum to form transportation vesicles. The cell utilizes this vesicle for membrane trafficking. Protein-lipid interactions, fluidity, and lateral pressure demonstrate the structural and functional characteristics of transporters, channels, and other integral membrane proteins. This chapter also discusses Electron Paramagnetic Resonance (EPR) and fluorescence spectroscopy in investigating the lipid environment and its interactions with membrane proteins.