ABSTRACT
Phospholipids laterally diffuse through bilayers as a result of acyl chain trans-gauche rotational isomerisms, and when they contact the protein interface, their lateral diffusion is reduced. The intrinsic order observed in protein-free phospholipid bilayers is therefore reduced when a protein is inserted into a bilayer. Molecular selectivity of the protein-phospholipid interface manifests itself in both functional and structural investigations. In the absence of selectivity, the lipids act as solvating species, maintaining the protein in a suitable form for activity and mobility. Biochemistry of the proteins and natural membranes, and the chemistry of the phospholipids and the probes used for the magnetic resonance experiments, need consideration when designing an experiment to study phospholipid-protein interations. Natural membranes may contain predominantly one integral or peripheral protein type, or a range of proteins. Only in the case of a biomembrane that contains one dominant protein can the information derived be interpreted as due to phospholipid interactions with a specific protein.
