4H9B

Radiation damage study of lysozyme - 0.70 MGy

Summary for 4H9B

• Entry DOI: 10.2210/pdb4h9b/pdb
• Related: 4H8X 4H8Y 4H8Z 4H90 4H91 4H92 4H93 4H94 4H9A 4H9C 4H9E 4H9F 4H9H 4H9I
• Descriptor: Lysozyme C, CHLORIDE ION, 1,2-ETHANEDIOL, ... (4 entities in total)
• Functional Keywords: hydrolase
• Biological source: Gallus gallus (bantam,chickens)
• Cellular location: Secreted: P00698
• Total number of polymer chains: 1
• Total formula weight: 14499.59

Authors

Sutton, K.A.,Snell, E.H. (deposition date: 2012-09-24, release date: 2013-05-15, Last modification date: 2017-11-15)

Primary citation

Sutton, K.A.,Black, P.J.,Mercer, K.R.,Garman, E.F.,Owen, R.L.,Snell, E.H.,Bernhard, W.A.
Insights into the mechanism of X-ray-induced disulfide-bond cleavage in lysozyme crystals based on EPR, optical absorption and X-ray diffraction studies.
Acta Crystallogr.,Sect.D, 69:2381-2394, 2013

PubMed Abstract: Electron paramagnetic resonance (EPR) and online UV-visible absorption microspectrophotometry with X-ray crystallography have been used in a complementary manner to follow X-ray-induced disulfide-bond cleavage. Online UV-visible spectroscopy showed that upon X-irradiation, disulfide radicalization appeared to saturate at an absorbed dose of approximately 0.5-0.8 MGy, in contrast to the saturating dose of ∼0.2 MGy observed using EPR at much lower dose rates. The observations suggest that a multi-track model involving product formation owing to the interaction of two separate tracks is a valid model for radiation damage in protein crystals. The saturation levels are remarkably consistent given the widely different experimental parameters and the range of total absorbed doses studied. The results indicate that even at the lowest doses used for structural investigations disulfide bonds are already radicalized. Multi-track considerations offer the first step in a comprehensive model of radiation damage that could potentially lead to a combined computational and experimental approach to identifying when damage is likely to be present, to quantitate it and to provide the ability to recover the native unperturbed structure.

PubMed: 24311579
DOI: 10.1107/S0907444913022117

Experimental method

X-RAY DIFFRACTION (1.1998 Å)