CLUSTERING OF FATTY-ACIDS IN PHOSPHOLIPID-BILAYERS

From electrophoresis experiments it is concluded that acidic phospholipids incorporated in liquid crystalline phosphatidylcholine bilayers at neutral pH are randomly distributed. The same is true for spin-labelled fatty acids. In contrast, long chain fatty acids are not fully ionized at neutral pH and appear to be clustered, i.e. they segregate out into patches. Only at pH>11 is the fatty acid-COOH group fully ionized and charge repulsion leads to a random distribution of the fatty acid within the plane of the bilayer. © 1979.