We intend to self-assemble new protein-cofactor supramolecular structures with enzymatic activity approaching or exceeding the efficiency of natural proteins. To overcome the key obstacles within this field, we are designing novel oxidoreductases without micking the complexity of natural protein structures. We have demonstrated that relatively simple water-soluble four α-helical protein scaffolds, known as maquettes, provide suffient foundation for multitude of oxidoreductase functions. Yet, many oxidoreductases involved in natural electron transport are membrane proteins, playing essential roles in cellular respiration, photosynthesis, and immune defense. The structural complexity of these biologically important proteins obscures studies of their structure-functional relationship. Therefore we are now exploring transmembrane amphililic maquettes as functional counterparts to the natural membrane oxidoreductases. These maquettes consist of four membrane-spanning α-helices linked into a single chain and contain binding sides for three porphyrin cofactors. Overexpression in E. coli inclusion bodies solved problems associated with insolubility and toxicity and enabled production in high yields. We recreated natural activities, including dioxygen binding, interprotein electron-transfer to natural cytochrome c, and quinol-cytochrome c oxidoreduction. The stable, readily expressible and biocompatible characteristics of these maquettes promise development of practical in vitro and in vivo applications.

Supramolecular self-assembly of amphiphilic synthetic redox proteins

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.