X-ray studies on phospholipid bilayers. I. Polymorphic forms of dimyristoyl lecithin.

A structural study of the synthetic phospholipid, L-alpha-dimyristoyl lecithin (DML), habs been made by X-ray fiber diffraction methods. Three different types of oriented specimens were prepared. They were X-ray photographed under the same conditions, including temperature and relative humidity. Three different types of diffraction patterns, corresponding to different conformations and/or packing arrangements, were found. They are characterized by their unit cell dimensions, space group, molecular conformations, and packing arrangements.