Electron diffraction studies of human erythrocyte membrane and its lipid extracts. Effects of hydration, temperature and hydrolysis.

The organization of lipid molecules in individual human erythrocyte ghost membranes and single bilayers of their total lipid extracts were studied by low-dose electron diffraction in a controlled environment. The highest onset temperature (Ts) at which diffraction rings corresponding to a gel state appeared, were found to be in the range of -2 to -4 degrees C for both the whole ghost membrane and bilayers of its total lipid extracts. The onsets were abolished by dehydration before separated crystallizations of cholesterol and phospholipid occurred. Ts increased as a result of free fatty acids accumulation in membranes after phospholipase A2 treatment or storage.