title: Exploring Structure, Dynamics, and Topology of Nitroxide Spin-Labeled Proteins Using Continuous-Wave Electron Paramagnetic Resonance Spectroscopy.
abstract: Structural and dynamical characterization of proteins is of central importance in understanding the mechanisms underlying their biological functions. Site-directed spin labeling (SDSL) combined with continuous-wave electron paramagnetic resonance (CW EPR) spectroscopy has shown the capability of providing this information with site-specific resolution under physiological conditions for proteins of any degree of complexity, including those associated with membranes. This chapter introduces methods commonly employed for SDSL and describes selected CW EPR-based methods that can be applied to (1) map secondary and tertiary protein structure, (2) determine membrane protein topology, (3) measure protein backbone flexibility, and (4) reveal the existence of conformational exchange at equilibrium.
authors.affiliation: Department of Chemistry and Biochemistry, Jules Stein Eye Institute, University of California, Los Angeles, California, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Altenbach
authors.affiliation: Department of Chemistry and Biochemistry, Jules Stein Eye Institute, University of California, Los Angeles, California, USA.
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: López
authors.affiliation: Institute of Organic and Medicinal Chemistry, University of Pécs, Pécs, Hungary.
authors.forename: Kálmán
authors.initials: K
authors.lastname: Hideg
authors.affiliation: Department of Chemistry and Biochemistry, Jules Stein Eye Institute, University of California, Los Angeles, California, USA. Electronic address: hubbellw@jsei.ucla.edu.
authors.forename: Wayne L
authors.initials: WL
authors.lastname: Hubbell
mesh_terms: D000818:Animals; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006801:Humans; D008565:Membrane Proteins / Q000032:analysis* / Q000737:chemistry; D056004:Molecular Dynamics Simulation; D009589:Nitrogen Oxides / Q000032:analysis*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D013113:Spin Labels
chemical_list: D008565:Membrane Proteins; D009589:Nitrogen Oxides; D013113:Spin Labels; C039900:nitroxyl
keywords: CW EPR; Distance measurements; EPR lineshape analysis; Nitroxide scanning; Protein dynamics; Protein structure; Site-directed spin labeling; Solvent accessibility; Spin interaction