I. Pascher, S. Sundell, H. Hauser
Dec 15, 1981
Citations
1
Influential Citations
53
Citations
Journal
Journal of molecular biology
Abstract
Abstract The conformation and molecular packing of 3-palmitoyl- dl -glycerol-1-phosphoryl-ethanolamine has been determined by a single crystal analysis (R = 0.115); it crystallizes in the monoclinic space group P2 1 a with a unit cell of a = 7.66 A , b = 9.08 A , c = 37.08 A and β = 90.2 ° , with four molecules per unit cell. The molecules exist as configurational and conformational enantiomers and pack in a bilayer arrangement. The phosphorylethanolamine groups have an orientation parallel to the layer surface. The hydrocarbon chains are arranged according to the T∥ chain packing mode and adopt an extreme tilt of 57.5 ° with respect to the layer normal. The free glycerol hydroxyl group forms an intramolecular hydrogen bond with, a phosphate oxygen and thus affects the conformation and orientation of the head group. The phosphorylethanolamine dipoles are oriented parallel to each other in double rows, while they are antiparallel and form a continuous network in dilauroylphosphatidylethanolamine (Elder et al., 1977). The area per molecule in 3-palmitoyl- dl -glycerol-1-phosphorylethanolamine (34.8 A2) is less than in diacylphosphatidylethanolamine (38.6 A2), indicating that in the latter the hydrocarbon chains determine the molecular cross-section. The significance of the interaction and space requirement of the phosphorylethanolamine group for the phase behaviour of phosphatidylethanolamine is discussed.