Self-regulation of the lipid content of membranes by non-bilayer lipids: ahypothesis

Many biological membranes contain lipids that do not form a lamellar phase but the roles of these lipids are not well understood. An artificial membra ne assembled from the main non-bilayer lipid and the major integral protein of pea thylakoids revealed that the protein spatially inhibits the formati on of non-bilayer structures in the lamellae, Without this inhibition, exce ss lipids are secreted, creating lipid reservoirs for metabolism and/or lat er uptake. This determines the protein:lipid ratio in the membrane and henc e the balance between structural flexibility and the stability of the key c onstituents that participate in cooperative interactions.