Lipid-protein interactions and lipoprotein reassembly

This chapter focuses on lipid–protein interactions and lipoprotein reassembly. The apolipoproteins (Apo) contain functional determinants that regulate several processes involved in lipid metabolism. ApoC-II is required for activation of lipoprotein lipase, the enzyme that clears the triglyceride-rich lipoproteins, very low-density lipoproteins (VLDL), and chylomicrons from circulation. Lipoprotein reassembly provides the biochemist with a powerful tool for testing current and new hypotheses. The major advantage that reassembled lipoproteins hold over their native counterparts is that they can be designed to contain a defined number of components so that a given physiological function can be assigned to one protein or even a protein fragment. One of the most important aspects of lipoprotein reassembly is to demonstrate that the overall physicochemical properties of the reassembled lipoproteins do not differ from those of native lipoproteins in any important way. The three methods that dominate the methodology of lipoprotein reassembly include (1) sonication of mixtures of lipids and proteins, (2) simple mixture of the components that depends upon spontaneous association, and (3) detergent removal methods.