CHAPTER 7. Membranes and Their Lipids: A Molecular Insight into Their Organization and Function

Abstract

Lipids are a highly diverse family of amphiphilic molecules that form the basis of biological membranes. These are fascinating molecules that assemble spontaneously into thin membrane leaflets without which life would not have evolved. Membranes possess unique physicochemical properties and functions, which cannot be understood solely on the individual lipid level but is ultimately linked to their unique 2D assembly into a membrane. To understand the structural and dynamic organization of membranes, ranging from the atomic level to a specific lipid and finally to the macroscopic lipid assembly, solid-state NMR in combination with high-resolution-like magic angle spinning (MAS) techniques has been invaluable over the last two decades. Here, we focus on solid-state MAS NMR of natural abundance nuclei, such as 31P, 14N, 13C and even 1H, as specific reporters that provide information about the hydrophilic membrane exterior and hydrophobic membrane core. We focus on three areas of membrane research: (i) the tracking of individual lipids in living/intact systems and obtaining their lipid profiles (lipidomics) in the hunt for promising biomarkers; (ii) the impact of individual lipids, namely oxidized phospholipids, on membrane organization; and (iii) the role of these lipids in apoptosis by regulating protein function at the mitochondrial membrane level.