This is the same experiment as Fig. 2a–c, showing proteinase K digestion profiles of other representative samples from patients with PD (n = 3) and patients with MSA (n = 3). The amplified product from the second round of α-syn-PMCA in samples of CSF from patients with MSA or patients with PD was incubated either without (–) or in the presence of increasing concentrations of proteinase K (0.001, 0.01, 0.1 and 1 mg ml−1) at 37 °C for 1 h. Proteins were separated on a 12% Bis-Tris gel and immunoblotted with the same antibodies as in Fig. 2 (SC N-19 (top), BD anti-α-syn clone 42 (middle) and SC 211 (bottom)). Each blot represents an individual sample. Molecular weight markers (kDa) are indicated on the left of the blot.