Aggregation of C-terminal truncated α-synuclein. Full-length α-Syn (70 μM) and truncated variants (70 μM) were incubated in PBS buffer, pH 7.4 with stirring at 37°C in the absence (white bar) or presence of 280 μM PQQ (black bar). Usually, the formation of total aggregations is monitored at 330 nm. However, PQQ has a typical absorbance at around 340 nm; so, the light scattering was monitored at 500 nm. n = 3 and error bar = standard deviation.