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Updated: Jul 19, 2026
09:23
Effect of Fluorescent Proteins on Fusion Partners Using Polyglutamine Toxicity Assays in Yeast
Published on: November 28, 2018
Fluorescence correlation spectroscopy shows that monomeric polyglutamine molecules form collapsed structures in
Scott L Crick1, Murali Jayaraman, Carl Frieden
1Department of Biomedical Engineering, Washington University, One Brookings Drive, Box 1097, St. Louis, MO 63130, USA.
Summary
Water acts as a poor solvent for polyglutamine peptides, causing them to form collapsed structures. This finding offers insights into polyglutamine aggregation, relevant to Huntington's disease.
Area of Science:
- Biophysics
- Polymer Science
- Neurodegenerative Disease Research
Background:
- Monomeric polyglutamine is known to be intrinsically disordered.
- Polyglutamine aggregation is implicated in the molecular mechanisms of Huntington's disease.
Purpose of the Study:
- To quantify the hydrodynamic sizes of monomeric polyglutamine chains.
- To investigate the solvent properties of water for polyglutamine.
- To understand the structural ensemble of monomeric polyglutamine.
Main Methods:
- Utilized fluorescence correlation spectroscopy (FCS) to measure translational diffusion times (tau(D)).
- Analyzed the scaling of diffusion times with polyglutamine chain length (N).
Main Results:
- Found that tau(D) scales with N as tau(o)N(nu), with nu = 0.32 +/- 0.02.
- Concluded that water is a polymeric poor solvent for polyglutamine.
- Observed that monomeric polyglutamine exists as a heterogeneous ensemble of collapsed structures.
Conclusions:
- The collapsed structure preference occurs despite the absence of hydrophobic residues.
- Results suggest implications for the thermodynamics and kinetics of polyglutamine aggregation.
- Provides a structural basis for understanding polyglutamine-related diseases.
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