INDUCED HELICAL CONFORMATION OF IONIC POLYPEPTIDES BY PHOSPHOLIPIDS SOLUBILIZED IN A NONIONIC SURFACTANT SOLUTION

Abstract
Phosphatidylcholine that has been solubilized in hexadecylpoly (oxyethylene) ether can induce a coil-to-helix transformation for poly(l-glutamic acid) in neutral solution. Similarly, solubilized phosphatidylserine promotes a helical conformation of poly(l-lysine) at neutral pH through complex formation. The mixed micelles of a phospholipid and a nonionic surfactant are thermodynamically stable and do not separate on standing. The nonionic surfactant here has no effect on the conformation of the two polypeptides.