Related Experiment Video
Updated: Aug 15, 2026

10:12
Protein Misfolding Cyclic Amplification of Prions
Published on: November 7, 2012
Structure of infectious prions: stabilization by domain swapping
Sichun Yang1, Herbert Levine, José N Onuchic
1Center for Theoretical Biological Physics, University of California San Diego, La Jolla, California 92093-0374, USA.
Summary
A new domain-swapped trimeric prion (DSTP) model offers a more favorable structure than the beta-helical prion trimer (BPT) for prion infectious units. This DSTP model may explain prion stability, inherited diseases, and prion strains.
Area of Science:
- Biochemistry
- Structural Biology
- Neuroscience
Background:
- The minimal infectious unit of prions is proposed as a beta-helical prion trimer (BPT), which can form amyloid fibrils.
- The BPT model lacks a clear mechanism for intermonomer binding, limiting understanding of prion structure and propagation.
Purpose of the Study:
- To propose and investigate an alternative structural model for prion oligomers: the domain-swapped trimeric prion (DSTP).
- To compare the stability and binding mechanisms of DSTP versus BPT using molecular dynamics simulations.
Main Methods:
- Molecular dynamics (MD) simulations were employed to analyze the structural and energetic properties of the proposed DSTP model.
- Comparison of intermonomer hydrogen bonding and proline dihedral strain energy between DSTP and BPT models.
Main Results:
- The DSTP model exhibits more favorable intermonomer hydrogen bonding and lower proline dihedral strain energy compared to the BPT model.
- The DSTP structure suggests potential mechanisms for prion stability, relevance to inherited prion diseases, and prion strain diversity.
Conclusions:
- The domain-swapped trimeric prion (DSTP) presents a compelling alternative to the BPT model for prion infectious units.
- Experimental validation using FRET is proposed to test the DSTP model.
- The DSTP model offers potential explanations for prion temperature stability, genetic links, and strain variation.
Related Concept Videos
Amyloid Fibrils
Amyloid fibrils are aggregates of misfolded proteins. Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils.
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining, normally used to...
Subviral Agents
Subviral agents are infectious entities that resemble viruses but lack one or more viral components, such as a capsid or essential replication machinery. These agents include viroids, prions, and satellites, each possessing distinct structural and functional characteristics that influence their mode of infection and replication.Viroids are the simplest subviral agents, consisting of circular, single-stranded RNA molecules without a protein coat. They exclusively infect plants, relying entirely...
Conservation of Protein Domains
Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
Conservation of Protein Domains Over Different Proteins
Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
Protein Folding
Overview
Protein Folding
Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence.
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
