Figure 4

Equine α-synuclein (α-syn) fragment peptide 62–86 generated fibrils after a longer lag phase period in comparison with its human counterpart using ThT binding assays. (A) Sequence of α-syn synthetic fragment peptides used to investigate aggregation propensity of equine α-syn. Aggregation scores determined by Tango bioinformatic program are provided in the right-sided column for each peptide fragment. Fragments exhibiting an aggregation score of 30–60 were selected as negative controls. Fragments with scores near or above 300 were further analyzed with biophysical assays to study the propensity of aggregation in vitro. (B) The maximum of fluorescence intensity at plateau phase of selected fragment peptides: bars show mean of fluorescence with error bars for SEM of three replicates. (C) Kinetics of α-syn fibril formation of human and equine fragment peptides 62–86. Data represent the mean of the fluorescence intensity with error bars for SEM obtained from three replicates. (D) Lag time required for fibril elongation of equine fragment peptide 62–86 is longer than for the human fragment peptide 62–86. Two-way analysis of variance with Bonferonni post-hoc testing to compare replicate means by row. Differences were considered statistically significant at * p < 0.05 and ** p < 0.01.