title: Radioprotectant screening for cryocrystallography.
abstract: Radiation damage continues to present a problem to crystallographers using cryocooled protein crystals at third-generation synchrotrons. Free-radical scavengers have been suggested as a possible means of reducing the rate of this damage. The screening of a large number of potential radioprotectants was undertaken with an online microspectrophotometer using cystine and cysteine to model protein disulfide bonds and thiol groups, respectively. Oxidized alpha-lipoic acid was tested as a possible model disulfide bond. The evidence for the effectiveness of ascorbate as a radioprotectant was strengthened, and quinone, 2,2,6,6-tetramethyl-4-piperidone, and reduced dithiothreitol showed promise as radioprotectants.
authors.affiliation: Laboratory of Molecular Biophysics, Department of Biochemistry, Rex Richards Building, South Parks Road, Oxford OX1 3QU, UK.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Southworth-Davies
authors.forename: Elspeth F
authors.initials: EF
authors.lastname: Garman
mesh_terms: D003198:Computer Simulation; D018360:Crystallography, X-Ray / Q000379:methods*; D004307:Dose-Response Relationship, Radiation; D011487:Protein Conformation / Q000528:radiation effects; D011489:Protein Denaturation / Q000528:radiation effects; D011506:Proteins / Q000737:chemistry* / Q000528:radiation effects* / Q000648:ultrastructure; D011829:Radiation Dosage; D011837:Radiation-Protective Agents / Q000737:chemistry*; D014965:X-Rays
chemical_list: D011506:Proteins; D011837:Radiation-Protective Agents