Chapter 4 - 13C NMR Studies of the Interactions of Fatty Acids with Phospholipid Bilayers, Plasma Lipoproteins, and Proteins

Abstract

This chapter focuses on the 13C NMR studies of the interactions of fatty acids with phospholipids' bilayers, plasma lipoproteins, and proteins. Unesterified fatty acids (FAs) are a key intermediate in lipid metabolism. They also constitute an important metabolic fuel in certain cells. The 13C NMR approach furnishes new and unique information about the structural and dynamic aspects of the binding of FA to albumin, providing insights into the structure of binding sites, the approximate locations of binding sites, and the molecular motions of FAs within the binding sites. Although albumin is too large for complete structure determination by NMR, fragments encompassing the domains and the two halves of the molecule can be achieved with the current technology. Monitoring FA exchange and partitioning in complex mixtures by 13C NMR has provided insights into how FAs might behave in biological systems. Results from these model systems provide a basic framework for interpreting data from the more complex cellular systems. The chapter concludes that the future contributions of 13C NMR would be to characterize the building of FAs to cell membranes, to monitor the partitioning of FAs between proteins and membranes, and to follow the movement of FAs from albumin to the plasma membrane and to the cytoplasm.