title: Seeing the heat -- preliminary studies of cryocrystallography using infrared imaging.
abstract: As preparation for an extensive study that aims to image the cryocooling process of macromolecular crystals, the ability to thermally image solid objects and liquids at temperatures far below 273 K is demonstrated. In the case of a large lysozyme crystal (1.0 x 0.7 x 0.2 mm), qualitative measurements show the cooling process to take about 0.6 s with the cooling taking place in a wave starting from the face of the crystal nearest to the origin of the cryostream and ending at the point furthest away from the origin. Annealing of this lysozyme crystal, cooled under good cryoprotectant conditions, shows that cold striations form perpendicular to the cooling stream. These striations become more pronounced after successive annealing. Cryocooling of a non-cryoprotected crystal of glucose isomerase displayed an 'S-shaped' cold front wave traveling across the sample. These preliminary results are qualitative but show the power of infrared imaging as a new tool for fundamental and practical cryocrystallography studies.
authors.affiliation: USRA at NASA Laboratory for Structural Biology, Code SD46, NASA MSFC, Huntsville, AL 35812, USA. eddie.snell@msfc.nasa.gov
authors.forename: Edward H
authors.initials: EH
authors.lastname: Snell
authors.forename: Russell A
authors.initials: RA
authors.lastname: Judge
authors.forename: Mike
authors.initials: M
authors.lastname: Larson
authors.forename: Mark J
authors.initials: MJ
authors.lastname: van der Woerd
mesh_terms: D003080:Cold Temperature; D003460:Crystallization; D018360:Crystallography, X-Ray; D006358:Hot Temperature; D006801:Humans; D007259:Infrared Rays; D007527:Isoenzymes / Q000528:radiation effects; D018499:Linear Energy Transfer / Q000528:radiation effects; D009113:Muramidase / Q000528:radiation effects; D012542:Scattering, Radiation; D014961:X-Ray Diffraction
chemical_list: D007527:Isoenzymes; D009113:Muramidase