Hydrophobic Interactions as Substitutes for a Conserved Disulfide Linkage in the Type IIa Bacteriocins, Leucocin A and Pediocin PA‐1

High and dry: Three analogues of leucocin A (shown in figure) and six analogues of pediocin PA-1 were synthesized in which conserved cysteines that form a disulfide bond were replaced by pairs of hydrophobic amino acids. Noncovalent hydrophobic interactions in all of the LeuA derivatives effectively replaced the disulfide and afforded peptides with full antimicrobial activity. In contrast, all of the Ped derivatives were inactive except for 5 d.