Structural analyzes for pre-formed fibrils (PFFs) with verification netrin-1 as an inhibitor of α-Synuclein fibrilization. (A) Thioflavin T assay showed that different aggregation rates of purified hα-Syn, hα-Syn + hNTN1 combination at different day of PFFs generation reactions. (B) hα-Syn + hNTN1 complex aggregate and form fibrils much less than hα-Syn only group on reaction day 10. Results are shown as means ± SEM; N = 3 independent experiments; **P < 0.01 by two-tailed Student’s t-test. (C) X-Ray diffraction pattern of partially aligned hα-Syn. (D) X-Ray diffraction pattern of partially aligned hα-Syn + hNTN1. (E) Negative stained TEM images of hα-Syn and hα-Syn + hNTN1 complex on day 10 (left). Coomassie blue staining results supported that each PFFs were generated under equal concentrations and ratios (right).