Room‐temperature macromolecular crystallography using a micro‐patterned silicon chip with minimal background scattering. Issue 3 (23rd May 2016)

• Record Type: Journal Article
• Authors: Roedig, Philip; Duman, Ramona; Sanchez-Weatherby, Juan; Vartiainen, Ismo; Burkhardt, Anja; Warmer, Martin; David, Christian; Wagner, Armin; Meents, Alke
• Is Part Of: Journal of applied crystallography. Volume 49:Issue 3(2016)
• Page Start: 968
• Page End: 975
• Publication Date: 2016-05-23
• Subjects: crystallography on a chip -- synchrotron serial crystallography -- room‐temperature crystallography -- X‐ray radiation damage; Crystallography -- Periodicals; 548.05
• DOI: 10.1107/S1600576716006348
• Languages: English
• ISSNs: 0021-8898

Abstract

Abstract : A micro‐patterned sample holder of single‐crystalline silicon, loaded with multiple protein crystals which are exposed to a humidified gas stream, allows high‐quality room‐temperature data collection. Abstract : Recent success at X‐ray free‐electron lasers has led to serial crystallography experiments staging a comeback at synchrotron sources as well. With crystal lifetimes typically in the millisecond range and the latest‐generation detector technologies with high framing rates up to 1 kHz, fast sample exchange has become the bottleneck for such experiments. A micro‐patterned chip has been developed from single‐crystalline silicon, which acts as a sample holder for up to several thousand microcrystals at a very low background level. The crystals can be easily loaded onto the chip and excess mother liquor can be efficiently removed. Dehydration of the crystals is prevented by keeping them in a stream of humidified air during data collection. Further sealing of the sample holder, for example with Kapton, is not required. Room‐temperature data collection from insulin crystals loaded onto the chip proves the applicability of the chip for macromolecular crystallography. Subsequent structure refinements reveal no radiation‐damage‐induced structural changes for insulin crystals up to a dose of 565.6 kGy, even though the total diffraction power of the crystals has on average decreased to 19.1% of its initial value for the same dose. A decay of the diffracting power by half is observed for a dose of D 1/2 = 147.5 ± 19.1 kGy, which is about 1/300 of the dose before crystals show a similar decay at cryogenic temperatures.