The ascent of manmade oxidoreductases

Speaker: Dr Ross Andersen, University of Bristol

Abstract:

Manmade protein maquettes - non-computationally designed, evolutionarily naive protein constructs - have proved highly adaptable to the inclusion of sophisticated engineering elements that support catalysis in natural oxidoreductases. By beginning with a generic sequence designed only to fold into a simple α-helical bundle fold and iteratively adding engineering elements onto the stripped-down protein chassis, the maquette approach allows the designer to avoid the imprinted complexity present in natural protein scaffolds. We have recently extended the maquette approach to address the fundamental issue of how manmade protein maquettes can be interfaced, and ultimately integrated, with natural living systems. 

Taking inspiration from nature and the simple engineering rules gleaned from the analysis of natural c-type cytochromes, we have demonstrated that a manmade protein maquette can be designed, expressed and processed through natural biochemical pathways in vivo to produce a fully functional, manmade c-type cytochrome without the need for further in vitro assembly - a hitherto unrealized feat in de novo protein design. This is achieved by utilizing the E. coli c-type cytochrome maturation apparatus to covalently anchor the heme cofactor to the maquette backbone with exceptional efficiency. The initial c-type cytochrome maquette reversibly binds molecular oxygen, achieves millisecond inter-protein electron transfer rates with a natural cytochrome (bovine cytochrome c) supported by simple complementary electrostatic surface patterning and, as a direct result of the covalent heme incorporation, provides an adaptable chassis in which elementary multi-heme electron transfer chains and photoactivatable porphyrin dyads can be assembled

Host: Dr Eva Hyde