Mass spectroscopic analysis of Sup35NM prion polymerization
Related Experiment Video
Updated: Aug 15, 2026
MALDI-ToF MS Method for the Characterization of Synthetic Polymers with Varying Dispersity and End Groups
Published on: October 3, 2025
1Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, USA. goncharov@wi.mit.edu
Abstract:
Sup35NM, the prion determining domain of the protein responsible for the yeast prion phenomenon [Psi], has become a powerful model for studying key processes in amyloid-related human diseases. One of these processes is a conformational conversion of soluble precursor protein into insoluble fibrillar structures. In this study, we created a set of Sup35NM mutants and used proteolytic digestion coupled with mass spectroscopy to monitor local structure of the protein during polymerization. Experimental data were compared to a network model and showed that during the conformational conversion residue Arg-28 became highly protected from cleavage, residue Arg-98 remained partially solvent exposed, and residues between 28 and 98 showed an intermediate degree of protection. In addition, we found that a distinct subset of proteolytic polypeptides spanning 28-98 residues segment spontaneously formed stable dimers. This finding suggests that the [29-98] region is the key interacting region of Sup35NM responsible for amyloid conversion.
Insights
Researchers studied the Sup35NM protein, a model for amyloid diseases, and found that the [29-98] region is crucial for its conversion into amyloid fibrils. This region forms stable dimers during the process.
Area of Science:
- Biochemistry
- Molecular Biology
- Neurodegenerative Disease Research
Background:
- The Sup35NM protein domain governs the yeast prion [Psi] and serves as a model for amyloid-related human diseases.
- Amyloid formation involves the conformational conversion of soluble proteins into insoluble fibrils.
Purpose of the Study:
- To investigate the structural changes in Sup35NM during polymerization.
- To identify key regions and residues involved in the amyloid conversion process.
Main Methods:
- Creation of Sup35NM mutants.
- Proteolytic digestion coupled with mass spectrometry to analyze protein structure.
- Comparison of experimental data with a network model.
Main Results:
- Residue Arg-28 became highly protected from cleavage during conformational conversion.
- Residue Arg-98 remained partially solvent-exposed, with intermediate protection for residues 28-98.
- A subset of proteolytic polypeptides spanning residues 28-98 spontaneously formed stable dimers.
Conclusions:
- The [29-98] region of Sup35NM is identified as the key interacting region responsible for amyloid conversion.
- The formation of stable dimers within the [29-98] segment suggests its critical role in the polymerization process.
More Related Videos
14:55Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
08:34OaAEP1-Mediated Enzymatic Synthesis and Immobilization of Polymerized Protein for Single-Molecule Force Spectroscopy
Published on: February 5, 2020