Can Fida characterise small molecule binding?

Yes: FIDA measurements delivers 2 major orthogonal readouts, I.e., the absolute in-solution hydrodynamic radius (Rh) and fluorescence intensity.

To increase data reliability, users withFIDA Neo detectors can also take advantage of ratiometric measurements to further enhance the sensitivity when analysing small-molecule interactions. We call this proprietary technology FIDA Lambda Dynamics, or just FIDA LD. It is based on fluorescent ratiometric measurements derived from standard FIDA experiments. Read more about FIDA Lambda Dynamics here.

In the case of small molecule interactions, FIDA assays can be performed in 3 different ways where:

1.     Global conformational changes upon small molecule treatment can be detected as a change in Rh.

2.     Small conformational changes that do not necessarily lead to change in global size of the target, could be detected as change in Tryptophan fluorescence at 280 nm excitation.

3.     Small molecule interactions can be analysed as shift in denaturation point by performing chemical unfolding assays in presence and absence of small molecule on Fida 1.

Read application note: ‘Exploring Small Molecule Interactions with Membrane Proteins’