Fig. 1. Synthesis of FL PrP-181 & 197PEG₂₇. (A) Final analysis of PrP 23-177-MESNA thioester via analytical RP-HPLC (linear gradient 5–65% ACN in 30 min), ESI-MS (expected mass: 16 931.6 Da, observed mass: 16 933 Da) and SDS-PAGE (lane 1: PrP 23-177-MESNA thioester, lane 2: LMW); (B) characterization of FL-PrP-178 β-mercapto-Asp-181 & 197PEG₂₇ via RP-HPLC, ESI-MS (expected mass: 25 786.6 Da, observed mass: 25 787 Da) and SDS-PAGE (lane 1: PrP 23-177-MESNA thioester, lane 2: FL-PrP-178 β-mercapto-Asp-181 & 197PEG₂₇); (C) characterization of FL-PrP-181 & 197PEG₂₇ via RP-HPLC, ESI-MS (expected mass: 25 754.6 Da, observed mass: 25 752 Da) and SDS-PAGE (lane 1: PrP 23-177-MESNA thioester, lane 2: FL-PrP-181 & 197PEG₂₇).