Heterogeneously seeded polymerization. ○, 0.05 mM PrP(108–144); ●, on day 12, S132-α-GalNAc fibril was added as a seed to the solution of 0.05 mM PrP(108–144); ◊, 0.075 mM S135-α-GalNAc; ▵, 0.075 mM S135-α-GalNAc + S135-β-GlcNAc fibril; ▿, 0.075 mM S135-α-GalNAc + PrP(108–144) fibril; ⧫, 0.075 mM S135-β-GlcNAc; ▴, 0.075 mM S135-β-GlcNAc + S132-α-GalNAc fibril; ▾, 0.075 mM S135-β-GlcNAc + PrP(108–144) fibril.