PHASES AND PHASE-TRANSITIONS OF THE HYDRATED PHOSPHATIDYLETHANOLAMINES

LIPIDAT is a computerized database providing access to the wealth of i nformation scattered throughout the literature concerning synthetic an d biologically derived polar lipid polymorphic and mesomorphic phase b ehavior. Here, a review of the LIPIDAT data subset refering to hydrate d phosphatidylethanolamines (PE) is presented together with an analysi s of these data. The PE subset represents 14% of all LIPIDAT records. It includes data collected over a 38-year period and consists of 1511 records obtained from 203 articles in 35 different journals. An analys is of the data in the subset has allowed us to identify trends in synt hetic PE phase behavior reflecting changes in lipid chain length, chai n unsaturation (number, isomeric type and position of double bonds), c hain asymmetry and branching, type of chain-glycerol linkage (ether vs . ester) and headgroup modification. Also included is a summary of the data concerning the effect of pH, stereochemical purity, and differen t additives such as salts, saccharides, alcohols, amino adds and alkan es on PE phase behavior. Information on the phase behavior of biologic ally derived PE is also presented. This review includes 236 references .