Final Activity Report Summary- PICK-CPP (Fluorescent caged phosphopeptides as probes to investigate glutamate receptors trafficking at the synapse level by modifications of PICK-AMPAR interactions)
The biological aim was to unravel the complexity of the dynamic intermolecular interactions that governed the formation, function and modulation of the gigadalton molecular nanomachine that was a synaptic connection between two neurons. Of crucial importance in this field were the interactions between glutamate receptors and PDZ domain scaffold proteins, which controlled receptor trafficking at the post-synapse, and thereby played a major role in synaptic plasticity, the molecular basis for memory coding. To reach this goal, a challenge in chemistry was to develop innovative approaches to overcome the current technological limits which arose when trying to monitor localised and dynamic events at the macromolecular sub-micron scale. Two specific aims were pursued:
1. monitoring or quantifying dynamic macromolecular interactions between key proteins in their native environment. This was performed by exploitation of the small size and the fluorescent properties of organic dyes.
2. direct and selective activation and deactivation of these same interactions with spatiotemporal control. This was performed by photo-control via the use of photolabile or photo-activatable groups.
During the course of this project, we:
1. developed new fluorogenic biochemical tools, i.e. peptide-based probes or proteins modified by semi-synthesis, for the monitoring of transient biological events involving protein-protein interactions and applied particularly in the study of synaptic plasticity.
2. developed photo-controllable ligands (peptide-based probes or proteins modified by semi-synthesis) for the activation and deactivation by light irradiation of monitoring of transient biological events involving protein-protein interactions and applied in particular to the study of synaptic plasticity.
3. performed the structural studies, using X-ray crystallography, of the domains and proteins involved in synaptic plasticity.