Related Experiment Video
Updated: Mar 14, 2026

Detection of Heterodimerization of Protein Isoforms Using an in Situ Proximity Ligation Assay
Published on: October 20, 2018
Linking in domain-swapped protein dimers.
Marco Baiesi1,2, Enzo Orlandini1,2, Antonio Trovato1,3
1Department of Physics and Astronomy, University of Padova, Padova, Italy.
Protein entanglement, measured by Gaussian entanglement (G'), is common in domain-swapped dimers. Nature favors negative entanglement and suppresses intertwining in longer protein dimers, impacting their properties.
Area of Science:
- Biophysics
- Structural Biology
- Biochemistry
Background:
- Knots are found in some single-domain proteins, influencing their properties.
- Domain-swapped protein dimers offer a model to study mutual chain entanglement in complexes.
Purpose of the Study:
- To investigate the role of mutual entanglement in protein complexes.
- To introduce and validate Gaussian entanglement (G") as a measure of chain intertwining.
Main Methods:
- Analysis of 110 non-redundant domain-swapped dimers.
- Calculation of Gaussian entanglement (G") to quantify intertwining.
- Numerical simulations of dimer dissociation.
Main Results:
- A significant fraction of domain-swapped dimers exhibit substantial intertwining (|G">1).
- Nature appears to favor configurations with negative mutual entanglement.
- Intertwining seems to be suppressed in longer protein dimers.
Conclusions:
- Gaussian entanglement (G") is a robust measure of protein chain entanglement.
- A novel topology-based classification for protein-swapped dimers is proposed.
- Entanglement may influence the physical and biological properties of protein complexes.
More Related Videos
12:05Production of Disulfide-stabilized Transmembrane Peptide Complexes for Structural Studies
Published on: March 6, 2013
09:37Combining Non-reducing SDS-PAGE Analysis and Chemical Crosslinking to Detect Multimeric Complexes Stabilized by Disulfide Linkages in Mammalian Cells in Culture
Published on: May 2, 2019
Related Concept Videos
Protein Complexes with Interchangeable Parts
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order...
Protein Complexes with Interchangeable Parts
Protein-protein Interfaces
Protein Folding
Protein Folding
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein and Protein Structure
A protein's shape is critical to its function. For example, an enzyme...