NWO/ECHO-project in collaboration with prof. Marc Koper and Dr.Ir. H.A. Heering
The objective of this project is to unravel the mechanism of redox-coupled processes in large respiratory enzyme complexes. In particular, membrane enzymes will be targeted that utilize the quinone pool as electron source or sink for the reduction/oxidation of water-soluble substrates. Current knowledge is biased to the half of the catalytic cycle in which substrate conversion takes place. However, the other half of the cycle, in which the active site is regenerated by intramolecular electron transfer and where crucial energy-conserving processes take place, remains poorly explored. The reason for this is that these processes are difficult to address in solution because only slow and indirect control of the redox processes in the enzymes can be achieved with freely diffusing components. Protein film voltammetry therefore is the method of choice to address this part of the mechanism, provided that a fast and well-defined electron transfer can be achieved. Here we aim to immobilize integral membrane enzymes on a rationally designed electrode surface that facilitates fast control and synchronization of the redox states of the cofactors. For this, the electrode surface will be modified with smart molecular wires that can directly plug into the quinone binding site.