P-31 NMR-STUDY OF MEMBRANE-STRUCTURE OF A LKYL PHOSPHATIDYLCHOLINE AND ITS LYSO-DERIVATIVES

Membrane structure and conformation of the phosphatidylcholine group o f -O-hexadecyl-2-palmitoyl-rac-glycerophosphocholine (1), 1-O-hexadecy l-sn-glycerophosphocholine (2), 1,2-di-O-hexadeecylyden-sn-glycerophos phocholine (3) and 1-O-hexadecyl-2-acetyl-sn-glycerophosphocholine (pl atelet activating factor) (4) have been investigated by P-31 NMR. It h as been shown that phospholipids (1-4) form bilayer structures under c onditions of incomplete hydration. Lysophosphatidylcholine (2) and its structural analogues (3, 4) formed micelles in the excess of water. A nisotropy of the chemical shift of phospholipids (1, 3, 4) was more th an two times greater as compared with lysophosphatidylcholine (2) in g el and liquid crystalline phase. The reason is the absence of fast rot ation around the C1-C2 bond of the glycerol residue of phospholipids ( 1, 3, 4).