title: A new spin on protein dynamics.
abstract: Site-directed spin labeling is a general method for investigating structure and conformational switching in soluble and membrane proteins. It will also be an important tool for exploring protein backbone dynamics. A semi-empirical analysis of nitroxide sidechain dynamics in spin-labeled proteins reveals contributions from fluctuations in backbone dihedral angles and rigid-body (collective) motions of alpha helices. Quantitative analysis of sidechain dynamics is sometimes possible, and contributions from backbone modes can be expressed in terms of relative order parameters and rates. Dynamic sequences identified by site-directed spin labeling correlate with functional domains, and so nitroxide scanning could provide an efficient strategy for identifying such domains in high-molecular weight proteins, supramolecular complexes and membrane proteins.
authors.affiliation: Dept Chemistry and Biochemistry, Jules Stein Eye Institute, University of California Los Angeles, Los Angeles, CA 90095, USA.
authors.forename: Linda
authors.initials: L
authors.lastname: Columbus
authors.forename: Wayne L
authors.initials: WL
authors.lastname: Hubbell
mesh_terms: D000818:Animals; D004268:DNA-Binding Proteins; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006801:Humans; D008958:Models, Molecular; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism; D012243:Rhodopsin / Q000737:chemistry / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism; D013113:Spin Labels
chemical_list: D004268:DNA-Binding Proteins; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins; D013113:Spin Labels; D012243:Rhodopsin; D011494:Protein Kinases