Engineering Electron Transferring Proteins and their Assembly at Electronic Interfaces

Many key cell functions are accomplished through complicated system of enzymes and redox carrier molecules that control electron and proton transport. Although significant number of these enzymes has been structurally characterized, the actual mechanism of redox catalysis is not always understood. Therefore we have adopted a different approach to address the structure-function relationship of oxidoreductases: we aim to uncover the assembly instructions required for function using smaller, simpler, more robust model proteins, maquettes. Our questions ask how many engineering elements are required to achieve a particular biological function, what are the individual biochemical and structural tolerances of these elements and how much of a protein infrastructure is consumed in accommodating the function. To start answering these questions, we have synthesized a set of amphiphilic maquettes. These maquettes transfer electrons across membranes, bind O2 and CO. They can be assembled on electrodic substrates through a variety of attachment strategies including simple adsorption, cysteine attachment to gold, histidine attachment to Ni-NTA, and click chemistry.