Figure 1

WT Syn interacts with preformed MTs and tubulin α₂β₂ tetramer.

(a) Representative Western blotting of Syn (0–32 μM) recovered in the supernatant (S) or pellet (P) fraction from co-sedimentation assays without (Syn) or after (Syn + MTs) incubation with preformed MTs (Tub) at constant total MT concentration (4 μM tubulin dimers). (b) Bound Syn plotted versus free Syn (r² = 0.94). The data reported in the plot derive from at least three different replicates. (c) Nano-ESI-MS spectra of 14 μM tubulin: the peak distributions relative to the tubulin dimer and the α₂β₂ tetramer are grouped by brackets, with the indication of the measured mass. (d) Overlay of spectra of 14 μM tubulin (black), and a mixture of 14 μM tubulin and 14 μM Syn (red), in the m/z range 4000–5200 (αβ dimer) or (e) in the m/z range 5600–7000 (α₂β₂ tetramer). The peaks corresponding to the α₂β₂/Syn complex are labelled by asterisks. (f) Magnification of panel e, in the m/z range 6100–6500. The arrows point to the peaks of the α₂β₂/Syn complex, labelled by the corresponding charge state. The measured mass of the complex is also indicated. In each panel, the most intense peak of each distribution is labelled by the corresponding charge state.