Raman study of effect of phospholipid chain unsaturation on bilayer phase transitions

Raman scattering has been used to study the gel to liquid-crystalline transition in several unsaturated mixed-chain, saturated mixed-chain, and unsaturated symmetric phospholipids. The results show that the large transition temperature widths in membranes containing unsaturated mixed-chain phospholipids in which the two acyl chains do not differ significantly in length are due mainly to the presence of the double bond and not to the asymmetry in the chains.