Characterization of lipid behaviour in model biomembranes using H-2 solid-state NMR

The interaction between the quadrupole moment of a deuteron and the electric field gradient of a carbon-deuterium bond on a lipid acyl chain perturbs the Zeeman splitting of the spin-1 deuteron in an orientation-dependent manner. Partial averaging of that perturbation by asymmetric reorientation of the acyl chains in lipid bilayers provides a powerful tool for probing and characterizing model membrane orientational order and phase behaviour. This chapter begins with a review of the quadrupole interaction as it pertains to H-2 solid-state NMR spectroscopy in lipid bilayers. It then goes on to describe how H-2 solid-state NMR spectroscopy is used to obtain acyl chain orientational order parameter profiles for liquid crystal phase lipid bilayers and to distinguish disordered and ordered lipid bilayer phases. The chapter continues with a discussion of how H-2 solid-state NMR spectroscopy has been used to characterize the phase behaviour of mixed-lipid bilayers and ends with a discussion of important contributions made to the determination of sterol-lipid phase diagrams using this approach.