Acquiring Structural Information on Virus Particles with Charge Detection Mass Spectrometry
David Z Keifer1, Tina Motwani2, Carolyn M Teschke2,3
1Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA.
Journal of the American Society for Mass Spectrometry
|March 30, 2016
Summary
Charge detection mass spectrometry analyzed bacteriophage P22 coat protein assembly. This technique revealed distinct mass distributions and capsid structures for A285Y and A285T variants, aiding in understanding protein assembly.
Area of Science:
- Biophysics
- Structural Biology
- Mass Spectrometry
Background:
- Bacteriophage P22 coat proteins self-assemble into procapsids.
- Understanding protein assembly is crucial for virology and nanotechnology.
- Charge detection mass spectrometry (CDMS) is a powerful tool for analyzing large biomolecular assemblies.
Purpose of the Study:
- To analyze the assembly products of two bacteriophage P22 coat protein variants (A285Y and A285T).
- To determine the mass and charge distributions of these assembly products using CDMS.
- To characterize the structures formed by these variants.
Main Methods:
- Charge detection mass spectrometry (CDMS) was employed as the primary analytical technique.
- Electrospray ionization was used to introduce the protein assemblies into the mass spectrometer.
- Chemical cross-linking was utilized to stabilize less stable protein particles.
Main Results:
- A285Y coat protein variants formed T = 3 and T = 4 procapsids with masses ranging from 5 to 15 MDa.
- A285T coat protein variants formed T = 4 and T = 7 procapsids with masses ranging from 5 to 25 MDa.
- Charge-to-size ratio analysis helped differentiate between hollow shells and compact structures.
Conclusions:
- CDMS successfully characterized the heterogeneous assembly products of P22 coat protein variants.
- The study provides insights into the structural diversity and assembly pathways of these proteins.
- The findings highlight the utility of CDMS for analyzing large, complex biomolecular systems.
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