Spin-Labeling EPR of Proteins: Dynamics and Water Accessibility of Spin-Label Side Chains
By introducing a side chain carrying a paramagnetic center (spin label, chemistry of spin labeling) at a desired site in a protein, one can obtain via EPR information on the dynamics of the side chain, its water accessibility, and the polarity of its microenvironment. Scanning those properties along the polypeptide chain can reveal details of the secondary and tertiary structure of the protein under investigation.
The subject of this entry is the application of site-directed spin labeling (SDSL) electron paramagnetic resonance (EPR) to characterize dynamics and water accessibility of specific sites in proteins. Some practical advantages of the use of EPR to study dynamics and water profiles in proteins should be emphasized. First of all the nitroxide label is relatively small and highly flexible, which enables its introduction at specific sites in proteins with minor perturbation of the protein structure. Second, SDSL EPR...
- Berliner LJ, editor. Spin labeling: theory and applications. New York: Academic; 1976.Google Scholar
- Berliner LJ, editor. Spin labeling II: theory and applications. New York: Academic; 1979.Google Scholar
- Berliner LJ, Reuben J, editors. Spin labeling theory and applications, Biological magnetic resonance. New York: Plenum Press; 1989.Google Scholar
- Bordignon E, Steinhoff HJ. Membrane protein structure and dynamics studied by site-directed spin-labeling ESR. In: Hemminga MA, Berliner LJ, editors. ESR spectroscopy in membrane biophysics, vol. 27. New York: Springer; 2007. p. 129–64.Google Scholar
- Brutlach H, Bordignon E, et al. High-field EPR and site directed spin labeling reveal a periodical polarity profile: the sequence 88–94 of the phototransducer NpHtrII in complex with sensory rhodopsin. NpSRII Appl Magn Reson. 2006;30:359–72.Google Scholar
- Kivelson D. Theory of EPR (electron paramagnetic resonance) line widths of free radicals. J Chem Phys. 1960;33:1094–106.Google Scholar
- Liang ZC, Freed JH. An assessment of the applicability of multifrequency ESR to study the complex dynamics of biomolecules. J Phys Chem B. 1999;103(30):6384–96.Google Scholar
- Volkov A, Dockter C, et al. Site-specific information on membrane protein folding by electron spin echo envelope modulation spectroscopy. J Phys Chem Lett. 2010;1(3):663–7.Google Scholar