Flow-through partial-filling affinity capillary electrophoresis for the detection of weak ligand-target interactions: application to coagulation factor XIIa

Coagulation factor XIIa (FXIIa) is a S1A serine protease implicated in several physiological pathways including the intrinsic coagulation pathway, the kallikrein-kinin system, and the immune response. In the field of thrombosis, anti-FXIIa therapies could answer unmet medical needs such as the safe prevention of thrombosis in patients exposed to blood-contacting devices. The FXIIa inhibition also rises as a therapeutic strategy in patients suffering from hereditary angioedema and as an emerging research field in neuro-inflammatory and neurodegenerative disorders.

The FXII or FXIIa inhibitors currently under development include peptides, proteins, antibodies, and RNA-based technologies. In contrast, only a few data regarding the design of synthetic small molecular-weight inhibitors of FXIIa are available. Our team previously developed 3-carboxamido-benzopyrans and highlighted that aromatic guanidine is an attractive starting point. To facilitate chemical exploration, we decided to apply a fragment-based lead discovery approach (FBLD). However, the success of this approach rests on the ability to develop bioassays that are able to detect affinity in the µM-mM range.

For this purpose, we develop a flow-through partial-filling affinity capillary electrophoresis designed to screen positively-charged molecules against FXIIa at physiological pH.