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Updated: Jun 23, 2026
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Analyzing Protein Architectures and Protein-Ligand Complexes by Integrative Structural Mass Spectrometry
Published on: October 15, 2018
Gas-phase unfolding and disassembly reveals stability differences in ligand-bound multiprotein complexes
Suk-Joon Hyung1, Carol V Robinson, Brandon T Ruotolo
1Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
Chemistry & Biology
|April 25, 2009
Summary
Ion mobility-mass spectrometry (IM-MS) reveals subtle ligand binding effects on protein stability, differentiating variant transthyretin responses to thyroxine. This technique enhances understanding for multiprotein drug design.
Area of Science:
- Biochemistry
- Analytical Chemistry
- Structural Biology
Background:
- Mass spectrometry (MS) is a common tool for studying small molecule-protein interactions.
- Subtle changes in protein assembly stability due to ligand binding are often undetectable by standard MS.
- Transthyretin (TTR) is a tetrameric protein involved in transporting thyroxine.
Purpose of the Study:
- To demonstrate that ion mobility-mass spectrometry (IM-MS) can detect subtle differences in ligand binding effects on protein stability.
- To compare the binding of thyroxine to wild-type TTR and disease-associated TTR variants using IM-MS.
- To highlight the potential of IM-MS for small-molecule drug design targeting protein complexes.
Main Methods:
- Utilizing ion mobility-mass spectrometry (IM-MS) to monitor protein subunit unfolding.
- Analyzing wild-type and disease-associated variants of tetrameric transthyretin.
- Comparing the stability changes upon ligand (thyroxine) binding between wild-type and variant TTR complexes.
Main Results:
- Standard MS indicated lower stability in variant TTR compared to wild-type TTR.
- IM-MS revealed that thyroxine binding confers a greater stability increase to variant TTR tetramers than to wild-type TTR tetramers.
- These findings highlight differential ligand-induced stabilization effects not apparent with conventional MS.
Conclusions:
- IM-MS offers enhanced sensitivity for detecting ligand-protein interactions and their impact on protein stability.
- The study provides a novel method for assessing the efficacy of small molecules in stabilizing protein assemblies.
- Results have significant implications for the rational design of drugs targeting multiprotein complexes, particularly for diseases associated with protein instability.
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