title: A generic protocol for protein crystal dehydration using the HC1b humidity controller.
abstract: Dehydration may change the crystal lattice and affect the mosaicity, resolution and quality of X-ray diffraction data. A dehydrating environment can be generated around a crystal in several ways with various degrees of precision and complexity. This study uses a high-precision crystal humidifier/dehumidifier to provide an airstream of known relative humidity in which the crystals are mounted: a precise yet hassle-free approach to altering crystal hydration. A protocol is introduced to assess the impact of crystal dehydration systematically applied to nine experimental crystal systems. In one case, that of glucose isomerase, dehydration triggering a change of space group from I222 to P21212 was observed. This observation is supported by an extended study of the behaviour of the glucose isomerase crystal structure during crystal dehydration.
authors.affiliation: Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, England.
authors.forename: Carina M C
authors.initials: CM
authors.lastname: Lobley
authors.affiliation: Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, England.
authors.forename: James
authors.initials: J
authors.lastname: Sandy
authors.affiliation: Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, England.
authors.forename: Juan
authors.initials: J
authors.lastname: Sanchez-Weatherby
authors.affiliation: Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, England.
authors.forename: Marco
authors.initials: M
authors.lastname: Mazzorana
authors.affiliation: Structural Genomics Consortium, University of Oxford, Roosevelt Drive, Headington, Oxford OX3 7DQ, England.
authors.forename: Tobias
authors.initials: T
authors.lastname: Krojer
authors.affiliation: Structural Genomics Consortium, University of Oxford, Roosevelt Drive, Headington, Oxford OX3 7DQ, England.
authors.forename: Radosław P
authors.initials: RP
authors.lastname: Nowak
authors.affiliation: Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, England.
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Sorensen
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry; D003460:Crystallization / Q000295:instrumentation / Q000379:methods*; D018360:Crystallography, X-Ray / Q000295:instrumentation / Q000379:methods*; D030562:Databases, Protein; D003890:Desiccation / Q000295:instrumentation / Q000379:methods*; D019286:Endopeptidase K / Q000737:chemistry; D004867:Equipment Design; D005656:Fungal Proteins / Q000737:chemistry; D005658:Fungi / Q000737:chemistry; D006801:Humans; D006813:Humidity; D008958:Models, Molecular; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D013302:Streptomyces / Q000737:chemistry; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D005656:Fungal Proteins; D011506:Proteins; D019286:Endopeptidase K; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase
keywords: cryoprotection; crystal dehydration; generic protocol; humidity control; macromolecular crystallization; room temperature