CONICET | Buscador de Institutos y Recursos Humanos

Protein-ligand interactions are associated to diverse biochemical process and their study can be used to develop selective detection systems, microscopy, and drug discovery. In the latter field, the screening methods are one of the most used tools since allows to find a few compounds in a large set, that has a desired biological activity.1 Fluorescence-based techniques are simple, economical, sensitive and therefore widely used in screening where the assays performed must be robust, sensitive and reproducible.In this context, the protein active site is selected as target and the use of specific fluorescent ligands in which the fluorescence signals (e.g. Intensity, anisotropy, lifetime, etc) change upon binds to protein pocket, are one way to achieve a fluorescence assay (Figure 1A).2 Many probes of this type were designed to monitor enzymatic activities where the probe is activated by a chemical reaction, thus the design of switching probes in non-enzymatic proteins is novel and desirable. For this purpose, our synthetic approach consists in coupling a fluorescent dye to an active ligand which binds to the protein target (Figure 1B).3We focused on two representative concepts of detection: (i) environment-sensitive probes exhibiting very weak fluorescence in a polar and / or protic medium, but strong fluorescence in a hydrophobic medium, 3-hydroxychromones (Figure 1C-i) 4 and (ii) probes of molecular rotors, where under irradiation an intramolecular charge transfer occurs through a non-radiative torsional relaxation pathway, thus being sensitive to changes in the medium´s viscosity, BODIPY (Figure 1C-ii). 5We will show the synthesis and fluorescence response of: 3-hydroxychromones and meso substituted BODIPYs, coupled to a specific ligand / inhibitor of Human Carboanhydrase II (hCA II, Figure 1C-iii), a protein model used as target detection.