title: The use of the Rx spin label in orientation measurement on proteins, by EPR.
abstract: The bipedal spin label Rx is more restricted in its conformation and dynamics than its monopodal counterpart R1. To systematically investigate the utility of the Rx label, we have attempted to comprehensively survey the attachment of Rx to protein secondary structures. We have examined the formation, structure and dynamics of the spin label in relation to the underlying protein in order to determine feasibility and optimum conditions for distance and orientation measurement by pulsed EPR. The labeled proteins have been studied using molecular dynamics, CW EPR, pulsed EPR distance measurement at X-band and orientation measurement at W-band. The utility of different modes and positions of attachment have been compared and contrasted.
authors.affiliation: Nucleic Acid Structure Research Group, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK. d.g.norman@dundee.ac.uk.
authors.forename: M A
authors.initials: MA
authors.lastname: Stevens
authors.affiliation: School of Physics and Astronomy, University of St Andrews, St. Andrews, KY16 9SS, UK.
authors.forename: J E
authors.initials: JE
authors.lastname: McKay
authors.affiliation: Nucleic Acid Structure Research Group, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK. d.g.norman@dundee.ac.uk.
authors.forename: J L S
authors.initials: JL
authors.lastname: Robinson
authors.affiliation: School of Physics and Astronomy, University of St Andrews, St. Andrews, KY16 9SS, UK.
authors.forename: H
authors.initials: H
authors.lastname: El Mkami
authors.affiliation: School of Physics and Astronomy, University of St Andrews, St. Andrews, KY16 9SS, UK.
authors.forename: G M
authors.initials: GM
authors.lastname: Smith
authors.affiliation: Nucleic Acid Structure Research Group, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK. d.g.norman@dundee.ac.uk.
authors.forename: D G
authors.initials: DG
authors.lastname: Norman
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D056004:Molecular Dynamics Simulation; D011506:Proteins / Q000737:chemistry*; D013113:Spin Labels
chemical_list: D011506:Proteins; D013113:Spin Labels