The molecular ruler

With the FRET method, the distance between two fluorescent probes, the donor and acceptor, can be measured. FRET is used throughout the natural sciences as it allows probing many molecular properties, such as interactions, activity (kinase,…), forces or structure, but also analytes (pH, calcium, chloride…) can be quantified via FRET biosensors.

We use FRET at the ensemble (cuvette or droplet) level, but over the years, we’ve also specialized in single molecule (sm) implementations of FRET. SmFRET is particularly popular in structural biology studies, as it is one of the few methods that can simultaneously quantify molecular conformation and conformational dynamics. In our research we characterized different FRET dye pairs, continuously refine our FRET analysis methods and try to increase the accuracy/precision of structure measurements, and push the time scales of conformational dynamics that we can probe. We also investigate different biological systems with smFRET.

Single-molecule based Förster resonance energy transfer can be used to measure in real time the distance between two fluorescent probes that are attached to a biomolecule with near Ångstrom precision. The main advantages of this approach are that the biomolecule does not need to be crystallized, does not need to be purified in large amounts, and can be assessed in real time in solution. On the one hand, we use this method to gain mere structural insights into proteins, and on the other hand, we use it to provide detailed insights into the intrinsic structural dynamics that some proteins possess. Some examples from our research: