Open AccessInvestigation of possible free‐radical scavengers and metrics for radiation damage in protein cryocrystallography
Author(s) -
Murray James,
Garman Elspeth
Publication year - 2002
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049502014632
Subject(s) - radiation damage , radiation , radical , undulator , lysozyme , chemistry , protein crystallization , radiochemistry , materials science , optics , physics , biochemistry , organic chemistry , crystallization
The introduction of highly intense wiggler and undulator beamlines has reintroduced the problem of X‐ray radiation damage in protein crystals even at cryogenic temperatures. Several metrics for monitoring radiation damage are considered and unit‐cell volume expansion is systematically investigated using crystals of three different types, but it is found to be too variable to be a useful metric. Radical scavengers of secondary radiation damage are investigated as possible mitigating agents. Styrene is found to be ineffective. A method of spectroscopically measuring the radiation damage with a microspectrophotometer was used and, in conjunction with crystallographic data, provided tentative but suggestive evidence for the efficacy of ascorbate as a free‐radical scavenging agent in cryocooled hen egg‐white lysozyme crystals.