Construction of a toroidal model for the magainin pore.

Magainins are natural peptides that selectively kill bacteria at concentrations that are harmless to animal cells. Due to a positive charge and distinct hydrophobic moment, magainins in the alpha-helical conformation interact favorably with bacterial membrane lipids. These interactions lead to the formation of large openings in the membrane and to the cell's death. The openings (toroidal pores) are supramolecular structures consisting of lipid and peptide molecules. A computer model of the pore in a bacterial membrane was constructed (see Figure) for the study of the molecular basis for magainin selectivity and specificity. Details of the construction and the preliminary equilibration of the pore model are given in this paper.