Sequential and specific exchange of multiple coiled-coil components

The capacity for sequential and specific exchange of single peptides from coiled-coil heterotrimers is investigated. Dual hydrophobic-hydrophilic interface systems permit iterative cycles of pH-triggered strand exchange that can specifically replace one, two, or even all three initial trimer components. The resultant new complexes are either resistant to or capable of further exchange. Control experiments demonstrate that background exchange among different complexes is negligible. When triggered, however, selective displacement of the same peptide from only one of two distinct heterotrimers is feasible. Previously documented peptidic cross-linking strategies remain operative in these more intricate environments.