High Bandwidth Sensing Of Single Protein Dynamics Using Nanopores And Dna Origami

Electrical detection using nanopores provides several advantages over classical protein sensing techniques, one being the extensive temporal bandwidth from microseconds to hours. We exploit this to tackle the broad-range kinetics of proteins using a combination of solid-state nanopores with DNA origami. Specifically, we anchor the protein of interest inside a nanopore and monitor its behavior by means of conductance changes over time. This represents a radically new strategy to resolve the characteristic features of protein function, namely conformational changes, as well as the binding, processing, and release of substrates & cofactors. Currently, we investigate the transcription repressor TetR, which controls anti-biotic resistance in bacteria by binding to the TetO operator. In our label-free experiments, we observe remarkably detailed state trajectories, revealing protein dynamics far beyond mere DNA-binding and dissociation. In combination with existing 3D structures, and molecular dynamics simulations, our approach opens a new way to unravel kinetic effects that were previously overlooked due to narrow bandwidths. We plan to apply our protein dynamics detector to many other protein systems, to obtain the broad-range kinetic information, which is urgently needed to understand protein function at the (sub-)molecular level.