Influence of BHA on the Thermotropic Behavior of Phospholipids

Abstract

The influence of butylhydroxylanisol (BHA) on the thermotropic behavior of phsopholipids was studied by differential scanning calorimetry (DSC). It was found to differ according to the polar headgroup of phospholipid. In the presence of dipalmitoylphosphatidylcholine (DPPC), BHA decreased the transition temperature (Tm), broadened the peak, and decreased the enthalpy of the transition. It caused the elimination of subtransition and pre-transition. With dipalmitoylphosphatidylethanolamine (DPPE), BHAdecreased Tm and broadened the peak, and two new subtransitions appeared. With dipalmitoylphosphatidylglycerol (DPPG), BHA had no influence on the profile. With a DPPC/DPPE mixture, BHA induced phase separation and the formation of a DPPC-rich domain. With a DPPC/DPPE mixture and the phospholipids of Escherichia coli, BHA had greater influence on the more fluid phospholipid species. BHA would thus appear to interact with a phospholipid near its polar head group, thereby affecting lipid packing.