Email this article Analysis of Saturation Recovery Amplitudes to Characterize Conformational Exchange in Spin-Labeled Proteins
- Authors: Bridges M.D.1, Yang Z.1,2, Altenbach C.1, Hubbell W.L.1
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Affiliations:
- Jules Stein Eye Institute and Department of Chemistry and Biochemistry, UCLA School of Medicine, University of California
- Department of Chemistry and Biochemistry, North Dakota State University
- Issue: Vol 48, No 11-12 (2017)
- Pages: 1315-1340
- Section: Original Paper
- URL: https://journals.rcsi.science/0937-9347/article/view/247924
- DOI: https://doi.org/10.1007/s00723-017-0936-3
- ID: 247924
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Abstract
Analysis of saturation recovery data from spin-labeled proteins is extended to include the amplitudes in addition to the recovery rates for two-site exchange. It is shown that the recovery amplitudes depend strongly on the exchange rate between states as well as their populations and this dependence provides a simple criterion to identify exchange rates in the 10–1000 kHz range. Analysis of experimental SR relaxation curves via the uniform penalty (UPEN) method allows for reliable identification of single, double, or other multiple-component traces, and global fitting of a set of relaxation curves using both relaxation rates and amplitudes determined from the UPEN fits allows for the estimation of exchange rate in the above domain. The theory is tested on simple model systems, and applied to the determination of conformational exchange rates in spin-labeled mutants of T4 Lysozyme and intestinal fatty acid binding protein. Finally, an example of T1-weighted spectral editing is provided for systems in the slow exchange limit.
About the authors
Michael D. Bridges
Jules Stein Eye Institute and Department of Chemistry and Biochemistry, UCLA School of Medicine, University of California
Email: hubbellw@jsei.ucla.edu
ORCID iD: 0000-0001-9999-9106
United States, Los Angeles, CA, 90095-7008
Zhongyu Yang
Jules Stein Eye Institute and Department of Chemistry and Biochemistry, UCLA School of Medicine, University of California; Department of Chemistry and Biochemistry, North Dakota State University
Email: hubbellw@jsei.ucla.edu
ORCID iD: 0000-0002-3018-3608
United States, Los Angeles, CA, 90095-7008; Fargo, ND, 58102
Christian Altenbach
Jules Stein Eye Institute and Department of Chemistry and Biochemistry, UCLA School of Medicine, University of California
Email: hubbellw@jsei.ucla.edu
United States, Los Angeles, CA, 90095-7008
Wayne L. Hubbell
Jules Stein Eye Institute and Department of Chemistry and Biochemistry, UCLA School of Medicine, University of California
Author for correspondence.
Email: hubbellw@jsei.ucla.edu
ORCID iD: 0000-0003-0577-3312
United States, Los Angeles, CA, 90095-7008
