CONICET | Buscador de Institutos y Recursos Humanos

Parkinson´s disease (PD) is a debilitating and incurable neurodegenerative diseasethat affects more than 1% of the population above 60 years-old. The combinationof genetic predispositions and external factors, such as compounds that promoteoxidative stress, promote the gain of toxic function of the protein alpha-Synuclein(aSyn), even in the absence of genetic mutations in its coding gene, SNCA, thatends up forming insoluble amyloid aggregates known as Lewy bodies. The identityof the toxic species responsible for PD remains elusive. In this context, we proposethat post-translational modifications (PTMs), as a well-known source of variabilityof proteins´ structure, function, and localization, may be responsible of triggeringthe pathological role of aSyn in neurons.We have generated a series of oxidative modifications on recombinant aSyn with aphoto-tunable method based on Ru complexes photosensitizer that promoteselectively Tyr-residues oxidation through a radical mechanism. This method hasbeen adapted to generate both covalent oligomers and nitrated monomers ofaSyn. On the other hand, we have also generated cathecolamine-modified andacetylated aSyn. We characterized these proteins variants by mass spectrometryto confirm PTMs positions and exposure of Tyr residues under differentconformational states. Biochemical characterization is underway to analyze theeffect of each PTM on amyloid aggregation, membrane binding and cytotoxicity inneuron-like cell cultures to evaluate their putative increase in toxicity.Finally, the systematic and reproducible production of modified aSyn is being usedto generate tools and methods, such as Nanobodies (VHHs) or MRM-MS, that couldquantitate specific PTMs in circulating aSyn as early biomarkers of PD pathology.