title: Global radiation damage: temperature dependence, time dependence and how to outrun it.
abstract: A series of studies that provide a consistent and illuminating picture of global radiation damage to protein crystals, especially at temperatures above ∼200 K, are described. The radiation sensitivity shows a transition near 200 K, above which it appears to be limited by solvent-coupled diffusive processes. Consistent with this interpretation, a component of global damage proceeds on timescales of several minutes at 180 K, decreasing to seconds near room temperature. As a result, data collection times of order 1 s allow up to half of global damage to be outrun at 260 K. Much larger damage reductions near room temperature should be feasible using larger dose rates delivered using microfocused beams, enabling a significant expansion of structural studies of proteins under more nearly native conditions.
authors.affiliation: Physics Department, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Warkentin
authors.forename: Jesse B
authors.initials: JB
authors.lastname: Hopkins
authors.forename: Ryan
authors.initials: R
authors.lastname: Badeau
authors.forename: Anne M
authors.initials: AM
authors.lastname: Mulichak
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Keefe
authors.forename: Robert E
authors.initials: RE
authors.lastname: Thorne
mesh_terms: D003460:Crystallization; D018360:Crystallography, X-Ray; D060733:Electromagnetic Radiation; D010940:Plant Proteins / Q000528:radiation effects; D011506:Proteins / Q000737:chemistry / Q000528:radiation effects*; D013696:Temperature; D013997:Time Factors
chemical_list: D010940:Plant Proteins; D011506:Proteins; C003427:thaumatin protein, plant