X-ray studies on phospholipid bilayers. VI. Comparative hydration effects on oriented films

Oriented films of three diacylphosphatidylethanolamines containing 12, 14 and 16 methylene groups in their hydrocarbon chains and one 14 carbon chain lecithin were studied by X-ray fiber diffraction. Their molecular conformations, packing arrangement, crystallographic and physico-chemical parameters as a function of hydration were determined. Basically the four phospholipids exhibit a common bilayer structure. However, they also present some interesting differences which might be relevant to their biological functions.