Can Fida 1 characterise small molecule binding?

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