Nanotemper present the first study confirming that binding-induced conformational changes can be quantified by SAW to determine binding affinities.
Surface Acoustic Wave (SAW) is a biosensor method that uses high-frequency waves. Upon interaction with molecules on the sensor surface, distinct characteristics of the acoustic waves are altered and can be recorded separately:
Changes in total mass on the biosensor result in a shift of the wave's phase. This phase shift provides information about the on and off-rates, as well as the stoichiometry of the interaction
An increase in flexibility of the molecules results in dampening of the wave's amplitude. This dampening directly reflects changes in the conformation of the molecules, eg after binding to compounds
SAW provides new insights to interaction mechanisms since it measures binding kinetics and conformational changes.
Binding of maltose to maltose-binding protein (MBP) results in major conformational rearrangements, which are reflected by a reduction of the wave's amplitude.
In this study, this signal is used to derive the binding affinity of the MBP-maltose interaction. So far, highly sensitive fluorescence detection was required to quantify conformational changes on such a small scale.
Surface Acoustic Wave sensors allow monitoring of intramolecular conformational transitions with impressive signal to noise ratios.SAW presents an ideal tool to investigate mechanisms of protein small-molecule interactions by separating mass binding and resulting conformational changes.
