Exchangeability of amino acid residues with similar physicochemical properties in coiled-coil interactions.

Systematic exchange of amino acid residues of similar physicochemical properties maintains specific coiled-coil interaction between two heptad repeats of HIV-1 gp41, as well as the biological activity of related peptide fusion inhibitors. This exchangeability can greatly degenerate sequence space of peptides thus making ab initio design of coiled-coil interaction feasible.