Membrane thickness and acyl chain length

Abstract

It appears reasonable to expect that the primary result of a change in the length of the acyl chains within a lipid bilayer is a similar change in the bilayer thickness. In the present communication we draw attention to the somewhat more complicated effects which are found experimentally for phosphatidylcholine bilayers as the hydrocarbon chain is varied from twelve to eighteen carbons in length. The major change in dimension which occurs with variation in acyl chain length is the area occupied per molecule rather than the bilayer thickness. The same effect is seen with solute hydrocarbon such as hexane which partition into the membrane and cause only a small variation in membrane thickness ..