Disruption of coiled coil formation by methionine oxidation

On the basis of previous data, we have designed a leucine-zipper peptide whose folding preferences are controlled by the oxidation state of a single methionine residue. The peptide Ac-Lys-Ala-Glu-Ile-Glu-Ala-Leu-Lys-Ala-Glu-Met-Glu-Ala-Leu-Lys-Ala-Glu-Ile-Glu-Ala-Leu-Lys -Ala-NH2 self-associates in aqueous media to form a parallel coiled coil, but the dimerization function of the peptide is abolished upon conversion of the methionine side chain to its sulfoxide form.