Find in Library

Microfocusing X-rays direct high-density photons on crystal samples and can enhance the diffraction limit and quality of collected data. However, these intense X-rays can cause radiation damage to the sample, which often results in undesirable structural information. Accordingly, a data collection strategy that minimizes radiation damage is critical to obtaining accurate structural information. In this study, radiation damage in single-point data collection was investigated at two different X-ray exposure times (1 s and 100 ms) using microfocusing X-rays and a thaumatin crystal larger than the beam. The data collection statistics showed that the diffraction intensity of the Bragg peak did not gradually decrease until the crystal rotation reached 180°, and it significantly decreased after exceeding this value. Thaumatin structures exposed to X-rays for 1 s (Thaumatin^1s) and 100 ms (Thaumatin^100ms) were determined at 1.13 Å resolution. The temperature factors for Asp60, Arg119, Lys163, and Lys187 of thaumatin were increased by radiation damage. Specific radiation damage was observed at the disulfide bond in Thaumatin^1s but was negligible in Thaumatin^100ms. Splitting and reprocessing Thaumatin^100ms showed that electron density maps with minimal radiation damage can be obtained when using minimal data that satisfy the completeness, I/sigma, and CC1/2 parameters. These results expand our understanding of radiation damage phenomena in macromolecules and can be used for data collection applications.