Accessibility of phosphatidylethanolamine in bacteriophage PM2 and in its gram-negative host.

The reaction of trinitrobenzenesulfonic acid with phosphatidylethanolamine in the cytoplasmic membrane of Alteromonas espejiana suggests that 50% of this lipid occupies the outer lamella. In PM2, similar analysis suggests that 56% of this lipid populates the outer lamella of the membrane, the surface of which accounts for 60% of the membrane area.