Chemical Synthesis of Alpha-Synuclein Proteins via Solid-Phase Peptide Synthesis and Native Chemical Ligation

Alpha-Synuclein (a-Synuclein) is a 140 amino acid protein implicated in neurodegenerative disorders known as synucleinopathies, where it accumulates in proteinaceous inclusions in the brain. The normal physiological function of a-Synuclein remains obscure, as it exists in several non-neuronal cells in which its function has not been studied. Given the tremendous interest in studying a-Synuclein, and the existing limitations in the production of modified forms of the protein, we developed a method for the chemical synthesis of a-Synuclein by combining peptide fragment synthesis via automated microwave-assisted solid-phase peptide synthesis and ligation strategies. Our synthetic pathway enables the synthesis of protein variants of interest, carrying either mutations or posttranslational modifications, for further investigations of the effects on the structure and aggregation behavior of the protein. Ultimately, our study forms the foundation for future syntheses and studies of other custom-made a-Synuclein variants with a single or several modifications, as necessary.