Radiation Damage of Myoglobin Crystals in Weak Stationary Electric and Magnetic Fields

17th Pan-American Synchrotron Radiation Instrumentation Conference

Trame, C.B.^1,2 ; Dragovic, M.^2 ; Chiu, H.-J.^1,2

Joint Center for Structural Genomics, United States^1

Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, United States^2

关键词: Crystalline samples;    Electric and magnetic fields;    Global radiation;    Magnetic and electric fields;    Molecular levels;    Protein crystal;    Radical scavengers;    Structural biology;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/493/1/012029/pdf
DOI  :  10.1088/1742-6596/493/1/012029

来源: IOP

【 摘 要 】

Radiation damage is one of the bottlenecks in the field of structural biology. Cryo-cooling of protein crystals provided a breakthrough in the 1980s and resulted in significant reductions in radiation damage. Other factors positively influencing the progression of damage include the application of radical scavengers and reductions in the experimental beam size. Here we study the impact on radiation damage of applying static magnetic and electric fields during protein diffraction experiments, ultimately probing the Lorenz force effect on primary photoelectrons and secondary Auger electrons, which both contribute to the damage process. The design of a special mounting pin using graphene for applying electric fields on a crystalline sample is described. Analyses of myoglobin protein crystals exposed to the fields of ∼40 mT and -300 V show a slower global radiation damage rate and also changes in the progression of specific damage process on the molecular level, in particular at doses extending beyond the Garman limit of 30 MGy.