We typically think of biologically relevant protein complexes forming spontaneously through surface complementarity. However, with the discovery of the mechanism of action (MoA) of Rapamycin & Cyclosporin in the early nineties, it became apparent that protein-protein interactions (PPIs) could be mediated by non-proteinaceous molecules. Furthermore, such interactions could have beneficial pharmacological effects such as the inhibition of the central regulatory kinase mTOR. Since this initial ground-breaking discovery, many other molecules…

It is well known, and accepted, that it is essential to have “high quality” protein at the outset of a target based, small molecule drug discovery campaign. But what does “high quality” mean?
Certainly biological activity is a must. A high degree of purity (typically ≥95%) is another crucial requirement. Most often “purity” is defined based on the presence of other proteins in the preparation, but the presence of small molecules, whether or not of biological origin, also needs to be considered. However, the aggregation state is only rarely considered, and yet it significantly impacts…

Is your biochemical assay not sensitive enough to characterize inhibitors with affinities of hundreds of µM?  Does your assay suffer from false readout from the intrinsic fluorescence of compounds at high concentration?  Did you know that Surface Plasmon Resonance (SPR) can be set up in such a way that the readout represents the biologically relevant interaction of two biological partners, and therefore it can directly detect compounds disrupting such interactions?