Fig. 4: Extracellular αSyn species in cerebrospinal fluid and in primary neuron media are not membrane-enveloped.

a Cerebrospinal fluid (CSF) collected from 6-month-old Tg-αSyn^A53T mice were subjected to limited proteolysis using indicated concentrations of proteinase K (PK) in the absence or presence of 0.1% Triton X-100. Immunoblots for αSyn protein levels (αSyn^pSer129, αSyn^Amyl, and αSyn^Fila), mature cathepsin-L (Cath-L^Mat), TSG101, and neuroserpin (n = 5 for αSyn^Amyl, αSyn^Fila, TSG101; n = 4 for αSyn^pSer129, Cath-L^Mat). b Media collected from Tg^x2-αSyn^A53T neuron cultures at DIV49 was subjected to limited proteolysis in presence or absence of 0.1% Triton X-100 and analyzed as in a (n = 3). All data represent means ± SEM. Each ‘n’ is an independent collection (CSF or medium) and proteolysis experiment. n.s. not significant; *P < 0.05; ****P < 0.0001 by 2-way ANOVA with Bonferroni multiple comparisons post-test (compared at each PK concentration).