Format

Send to

Choose Destination
J Am Chem Soc. 2011 Mar 30;133(12):4156-9. doi: 10.1021/ja107650c. Epub 2011 Mar 9.

Monitoring structural transitions in icosahedral virus protein cages by site-directed spin labeling.

Author information

1
Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA.

Abstract

This work describes an approach for calculating and measuring dipolar interactions in multispin systems to monitor conformational changes in icosahedral protein cages using site-directed spin labeling. Cowpea chlorotic mottle virus (CCMV) is used as a template that undergoes a pH-dependent reversible capsid expansion wherein the protein cage swells by 10%. The sequence-position-dependent geometric presentation of attached spin-label groups provides a strategy for targeting amino acid residues most probative of structural change. The labeled protein cage residues and structural transition were found to affect the local mobility and dipolar interactions of the spin label, respectively. Line-shape changes provided a spectral signature that could be used to follow the conformational change in CCMV coat dynamics. The results provide evidence for a concerted swelling process in which the cages exist in only two structural forms, with essentially no intermediates. This methodology can be generalized for all symmetry types of icosahedral protein architectures to monitor protein cage dynamics.

PMID:
21388197
DOI:
10.1021/ja107650c
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for American Chemical Society
Loading ...
Support Center