Abstract

Frontier in Direct Observation and Visualization of Molecular Interactions

Gijs Wuite, Professor, Vrije Universiteit Amsterdam

The genetic information of an organism is encoded in the base pair sequence of its DNA. Many specialized proteins are involved in organizing, preserving and processing the vast amounts of information on the DNA. In order to do this swiftly and correctly these proteins have to move quickly and accurately along and/or around the DNA constantly rearranging it. In order to elucidate these kind of processes we perform single-molecule experiments on model systems such as restriction enzymes, DNA polymerases and repair proteins. The data we use to extract forces, energies and mechanochemistry driving these dynamic transactions. The results obtained from these model systems are then generalized and thought to be applicable to many DNA-protein interactions. In particular, I will report on a new single molecule methods. I’ll introduce Acoustic Force Spectroscopy (AFS). With AFS we extend the force-spectroscopy toolbox with an acoustic manipulation device that allows exerting acoustic forces on tethered molecules. AFS is a Lab-on-a-chip device consisting of a flow cell of two glass plates with a fluid chamber in between and a piezo element glued on top. While applying an alternating voltage to the piezo element, forces from sub-pN to hundreds of pNs are exerted to thousands of biomolecules in parallel, with sub-millisecond response time and inherent stability. AFS distinguishes itself by its relative simplicity, low cost and compactness, which allow straightforward implementation in lab-on-a-chip devices. I’ll discuss the application of this technique to DNA-protein interaction as well as for antibody-protein interaction detection and for its use to quantify cell adhesion.