Dependence of the main phase transition temperatures of diacyl phospolipids with mixed and identical saturated acyl chains on the chain volumes

Statistical analysis of quantitative structure—property relationships (QSPR) for the phase transition gel—liquid crystal (main phase transition) temperatures (Tm) in hydrated vesicle bilayers of diacyl phosphatidylcholines (PC) and diacyl phosphatidylethanolamines (PE) with saturated acyl chains was carried out. Multiple regression equations relating the Tm values to the volumes of the hydrocarbon fragments of the sn-1 and sn-2 acyl chains show that the acyl groups influence the transiton temperatures Tm in different manner, the effect of the sn-2 group being predominant. The transition temperatures Tm of saturated phosphatidylethanolamines and diacyl phosphatidylglycerols can be predicted using the Tm values calculated for the corresponding diacyl phosphatidylcholines.