title: In vacuo X-ray data collection from graphene-wrapped protein crystals.
abstract: The measurement of diffraction data from macromolecular crystal samples held in vacuo holds the promise of a very low X-ray background and zero absorption of incident and scattered beams, leading to better data and the potential for accessing very long X-ray wavelengths (>3 Å) for native sulfur phasing. Maintaining the hydration of protein crystals under vacuum is achieved by the use of liquid jets, as with serial data collection at free-electron lasers, or is side-stepped by cryocooling the samples, as implemented at new synchrotron beamlines. Graphene has been shown to protect crystals from dehydration by creating an extremely thin layer that is impermeable to any exchanges with the environment. Furthermore, owing to its hydrophobicity, most of the aqueous solution surrounding the crystal is excluded during sample preparation, thus eliminating most of the background caused by liquid. Here, it is shown that high-quality data can be recorded at room temperature from graphene-wrapped protein crystals in a rough vacuum. Furthermore, it was observed that graphene protects crystals exposed to different relative humidities and a chemically harsh environment.
authors.affiliation: Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, England.
authors.forename: Anna J
authors.initials: AJ
authors.lastname: Warren
authors.affiliation: Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, England.
authors.forename: Adam D
authors.initials: AD
authors.lastname: Crawshaw
authors.affiliation: Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, England.
authors.forename: Jose
authors.initials: J
authors.lastname: Trincao
authors.affiliation: Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, England.
authors.forename: Pierre
authors.initials: P
authors.lastname: Aller
authors.affiliation: Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, England.
authors.forename: Simon
authors.initials: S
authors.lastname: Alcock
authors.affiliation: Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, England.
authors.forename: Ioana
authors.initials: I
authors.lastname: Nistea
authors.affiliation: Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, England.
authors.forename: Paula S
authors.initials: PS
authors.lastname: Salgado
authors.affiliation: Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, England.
authors.forename: Gwyndaf
authors.initials: G
authors.lastname: Evans
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000737:chemistry; D000818:Animals; D002645:Chickens; D003460:Crystallization / Q000379:methods; D018360:Crystallography, X-Ray / Q000379:methods*; D006108:Graphite / Q000737:chemistry*; D032426:Marantaceae / Q000737:chemistry; D009113:Muramidase / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D013302:Streptomyces / Q000201:enzymology; D013696:Temperature; D014618:Vacuum; D014867:Water / Q000737:chemistry
chemical_list: D010940:Plant Proteins; D011506:Proteins; D014867:Water; C003427:thaumatin protein, plant; D006108:Graphite; C421864:hen egg lysozyme; D009113:Muramidase; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase
keywords: dehydration; graphene; room temperature; vacuum