Interaction of the pore-forming domain of colicin A with phospholipid vesicles

Abstract
The interaction of the 20-kDa pore-forming domain of colcin A with phospholipid vesicles was investigated by gel permeation chromatography, analytical centrifugation, and electron microscopy. Under the experimental conditions of this study, this peptide was found to interact only with vesicles containing negatively charged phospholipids. It forms a well-defined dislike complex with phosphatidyglycerols with a preference for those containing 12-14 atoms of carbon in their fatty acid chain. This complex has a diameter of 120 .ANG. and is about one bilayer thick. It contains nine molecules of peptide and is formed both at acidic pH (pH 5.0) and at neutral pH (pH 7.2).