Hydrophilic to amphiphilic design in redox protein maquettes

De novo protein design has created small, robust protein–cofactor complexes that serve as simplified working models, or maquettes, for the much more complicated natural oxidoreductases. We review the research avenues that spring from the better characterized water-soluble hydrophilic maquettes and guide the construction of amphiphilic maquettes patterned on membrane-bound oxidoreductases that couple electron transfer to transmembrane proton-motive force. We address the special working challenges and opportunities that arise with amphiphilic maquettes designed to assemble in membranes, along with the redox and pigment cofactors required to promote light activated electron transfer, redox-coupled electric field generation, proton exchange and transmembrane charge motion.