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Intense synchrotron radiation produces specific structural and chemical damage to proteins even at 100 K. Disulfides form radicals [1] or break, acidic residues are decarboxylated and the active site of enzymes appear particularly radiation-sensitive. The physical state of the crystal solvent plays an important role in radiation damage. Amorphous at 100 K, the solvent undergoes a glass transition and crystallizes upon warming, at temperatures that depend on the size of the solvent channels within the crystal [2]. The temperature-dependence of specific radiation damage was assessed by collecting a series of data sets on a single crystal of the enzyme acetylcholinesterase at two temperatures, one below (100 K) and one above (155 K) the glass transition of the crystal solvent [3]. Besides increased damage to sulfur-containing groups, conformational changes in the catalytic triad at the active site were observed above the solvent glass transition. These results show that at 155 K the protein has acquired sufficient conformational flexibility to adapt to irradiation-induced alterations in the conformational energy landscape. They reveal the influence of both protein and solvent dynamics on specific radiation damage to proteins.