ORCID
https://orcid.org/0009-0004-8472-1215
Date of Award
Spring 2026
Language
English
Embargo Period
4-29-2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
College/School/Department
Department of Chemistry
Program
Chemistry
First Advisor
Qiang Zhang
Committee Members
Qiang Zhang, Pan Li, Maksim Royzen, Alexander Shekhtman, Ting Wang,
Keywords
Glycoprotein
Subject Categories
Amino Acids, Peptides, and Proteins | Organic Chemicals
Abstract
Prion diseases are fatal neurodegenerative disorders initiated by conformational misfolding of the prion protein (PrP), which generates pathogenic conformers that propagate via templated conversion and accumulate as aggregates. Glycosylation can modulate the PrP folding energy landscape, thereby biasing folding trajectories and the distribution of resulting conformational states. Bank vole PrP contains two N-linked glycosylation sites, and disentangling the contributions of site occupancy versus glycan structure requires homogeneous, site-defined glycoforms. In contrast, biosynthetic expression typically produces heterogeneous glycoform ensembles due to multistep Golgi processing, precluding independent control of glycan identity at each site. Here we report a chemical synthesis strategy of bank vole PrP(23–231) with site-defined glycosylation. Glycopeptide segments were prepared by on-resin Lansbury aspartylation, and fragment assembly was accomplished using a β-thiolactone-enabled ligation strategy suited to sterically congested junctions. A key Val–Thr linkage is intrinsically difficult to forge because β-branching at both residues increases steric congestion at the coupling interface; thiolactone activation provides an irreversible thermodynamic driving force that enables productive coupling under conditions compatible with unprotected glycopeptides. The ligation proceeds without an external thiol additive, and the crude reaction mixture can be advanced directly into downstream operations, including conversion to the native linkage. Using this workflow, we obtained homogeneous bank vole PrP(23–231) bearing GlcNAc monosaccharides at both N-glycosylation sites. This modular route affords systematic access to defined PrP glycoforms and establishes a chemically tractable entry point for subsequent installation of complex and asymmetric N-glycans, thereby enabling mechanistic interrogation of how glycosylation influences PrP misfolding and pathogenic conformational outcomes.
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Tian, Baotong, "Studies towards Chemical Synthesis of Homogeneous Prion Glycoprotein" (2026). Electronic Theses & Dissertations (2024 - present). 419.
https://scholarsarchive.library.albany.edu/etd/419