Cholesterol-induced Conformational Change in the Sphingomyelin Headgroup (Biophysical Journal)

Sphingomyelin (SM) and cholesterol (Cho) are the important lipids for the formation of biologically functional membrane domains, lipid rafts. However, the interaction between Cho and the headgroup of SM remains unclear. In this study, we performed solid-state NMR experiments to reveal the Cho effects on the headgroup conformation using 2H-labeled stearoyl-SM (SSM). Deuterated SSMs at the C?, C?, and C? positions of a choline moiety were separately prepared and subjected to NMR measurements to determine the quadrupolar splitting of 2H signals in hydrated SSM unitary and SSM/Cho (1:1) bilayers.