Year: 2002
Type: conference-abstract
Abstract: Intense synchrotron radiation produces specific structural and chemical damage to proteins even at 100 K. Disulfide bonds break or elongate, acidic residues are decarboxylated and the active site of enzymes appear particularly radiationsensitive.Chemically identical groups in a given protein are not equally radiation-sensitive.Differences in solvent accessibility and in the chemical and dynamical nature of the close environment are most likely among the crucial factors that determine radiation-sensitivity of a specific residue.Another factor that plays an important role in radiation damage is the physical state of the crystal solvent.Solvent in trigonal crystals of the enzyme Torpedo californica acetylcholinesterase (TcAChE) crystallizes upon warming at 155 K, thus providing circumstantial evidence for the occurrence of a glass transition at or below 155 K.The temperature-dependence of specific radiation damage was assessed by collecting a series of data sets on a single crystal of TcAChE at two temperatures, one below and one above the glass transition of the crystal solvent, viz. at 100 and at 155 K, respectively [1].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.
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2019220394