Conformational analysis of mixed monolayers of phorbol ester and phospholipid.

A computational approach was used to study the conformation of mixed monolayers of amphiphilic molecules in order to characterize the assemblage of phospholipids around tumor-promoting and biologically inactive phorbol esters. The theoretical model was in fair agreement with both experimental data obtained in mixed monolayers of phorbol esters and dipalmitoylphosphatidylcholine spread at an air-water interface and the binding of phorbol esters to phospholipid bilayers. Thus, the present method may represent a useful tool to predict the orientation and molecular interaction of amphiphilic drugs at the membrane level.