100 μg of protein of each neuron sample was reduced with tris(2-carboxyethyl)phosphine (TCEP), alkylated with iodoacetamide and digested with trypsin overnight at 37°C. Labelling of tryptic peptides with Tandem mass tag (TMT) 6-plex reagents (Thermo Fisher) was carried out according to manufacturer’s instructions. The combined TMT labelled samples were cleaned up using C18 tips before analyzing by LC-MS/MS.
