The interaction of a recombinant cecropin/melittin hybrid peptide with the outer membrane of Pseudomonas aeruginosa.

A cecropin/melittin hybrid peptide (CEME) produced by recombinant DNA procedures was tested for its ability to interact with the outer membrane of Pseudomonas aeruginosa and found to have identical biological properties to that of chemically synthesized CEME. CEME was shown to kill P. aeruginosa and permeabilize its outer membrane to lysozyme and 1-N-phenylnaphthlyamine, in some cases better than other antimicrobial agents and permeabilizers. CEME demonstrated a high-binding affinity to purified P. aeruginosa lipopolysaccharide (LPS) and LPS in whole-cell environments. These data provide information on the molecular mechanism of CEME antimicrobial activity and strongly suggest that it is taken up across the outer membrane by the self-promoted uptake pathway.