showing that cholesterol significantly increases lipid motion correlation times, further illustrating its role in modulating membrane properties. In addition, Roberts et al. investigated phospholipid dynamics in vesicles, revealing that 31 P relaxation rates reflect varied lipid motion profiles in bilayers. They identified a residual dipolar interaction between phosphorus and nearby glycerol C3 protons, providing estimates of the P-H vector orientation relative to the membrane surface. This method was also used to monitor the interaction of micelles of PC with the peripheral membrane protein Bacillus thuringiensis phosphatidylinositol-specific phospholipase C (PI-PLC). This interaction helps anchor the enzyme to the membrane, highlighting the importance of lipid-protein interactions in regulating enzyme activity.