Magnetic resonance studies of lipid-protein interfaces and lipophilic molecule partitioning.

Lipophiles, including local and other general anesthetics, may partition into various locations of biological membranes, and the degree of partitioning depends upon various membrane properties including the electrostatics as well as the lipophile ionization state. Magnetic resonance methods such as spin-label electron spin resonance (ESR) and deuterium nuclear magnetic resonance (’H-NMR) each show spectral properties that can be exploited to identify the various locations of lipophiles in biomembranes as well as determine directly the ionization state of a lipophile while in the bilayer. In recent studies on nicotinic acetyl choline receptor (nAChR) rich membranes and protein-free model membranes, we suggest that: