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Pressure‐induced high‐density amorphous ice in protein crystals
Author(s) -
Kim Chae Un,
Chen YiFan,
Tate Mark W.,
Gruner Sol M.
Publication year - 2008
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889807048820
Subject(s) - mosaicity , amorphous ice , ice crystals , protein crystallization , diffraction , crystallization , amorphous solid , crystal (programming language) , materials science , crystallography , x ray crystallography , scattering , chemistry , optics , physics , programming language , organic chemistry , computer science
Crystal cryocooling has been used in X‐ray protein crystallography to mitigate radiation damage during diffraction data collection. However, cryocooling typically increases crystal mosaicity and often requires a time‐consuming search for cryoprotectants. A recently developed high‐pressure cryocooling method reduces crystal damage relative to traditional cryocooling procedures and eases or eliminates the need to screen for cryoprotectants. It has been proposed that the formation of high‐density amorphous (HDA) ice within the protein crystal is responsible for the excellent diffraction quality of the high‐pressure cryocooled crystals. This paper reports X‐ray data that confirm the presence of HDA ice in the high‐pressure cryocooled protein crystallization solution and protein crystals analyzed at ambient pressure. Diffuse scattering with a spacing characteristic of HDA ice is seen at low temperatures. This scattering then becomes characteristic successively to low‐density amorphous, cubic and hexagonal ice phases as the temperature is gradually raised from 80 to 230 K, and seems to be highly correlated with the diffraction quality of crystals.