FIGURE 5.

EGCG significantly reduces the seeding capacity of FapC fibrils. Seeds were preincubated with EGCG at an EGCG:protein molar ratio of 0, 1, 2, 4, 8, 16, 32, and 64. Subsequently, 5% seeds were added to 95% FapC monomer to a total concentration of 0.5 mg/ml and incubated with ThT. A, ThT fluorescence assay. The direction of the arrow indicates higher EGCG concentration. The panel shows the full time scale of 150 h including a non-seeded control (gray). B, initial slope of ThT fluorescence normalized to the signal from the sample without EGCG. Error bars denote S.D. (n = 3). C, far-UV CD spectra of FapC monomer and FapC fibrils incubated with and without EGCG showing a marked change in the FapC fibril structure upon incubation with EGCG. a.u., arbitrary units; MRE, mean residue ellipticity; deg, degrees.