In vitro modifications of alpha-synuclein by DOPAL

Samples of modified aS were prepared by adding 1.25 mM DOPAL to 67 or 300 μM aS solution in 50 mM phosphate buffer, pH 7.4. Two different set of samples have been prepared: with and without NaBH₃CN as a reducing agent. In both cases reaction mixtures were allowed to react at 37 °C for 5 hours, protected from light. Samples aliquots were collected at different time points, loaded onto a gradient 4–20% SDS-PAGE and stained with Comassie blue. When the reaction was carried out in order to perform further experiments, the final reaction product was extensively dialyzed against PBS to eliminate DOPAL non bound to aS.