Effective scavenging at cryotemperatures : further increasing the dose tolerance of protein crystals

The rate of radiation damage to macromolecular crystals at both room temperature and 100 K has previously been shown to be reduced by the use of certain radical scavengers. Here the effects of sodium nitrate, an electron scavenger, are investigated at 100 K. For sodium nitrate at a concentration of...

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Détails bibliographiques
Publié dans:Journal of synchrotron radiation. - 1994. - 18(2011), Pt 3 vom: 18. Mai, Seite 346-57
Auteur principal: De la Mora, Eugenio (Auteur)
Autres auteurs: Carmichael, Ian, Garman, Elspeth F
Format: Article en ligne
Langue:English
Publié: 2011
Accès à la collection:Journal of synchrotron radiation
Sujets:Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Proteins
Description
Résumé:The rate of radiation damage to macromolecular crystals at both room temperature and 100 K has previously been shown to be reduced by the use of certain radical scavengers. Here the effects of sodium nitrate, an electron scavenger, are investigated at 100 K. For sodium nitrate at a concentration of 0.5 M in chicken egg-white lysozyme crystals, the dose tolerance is increased by a factor of two as judged from the global damage parameters, and no specific structural damage to the disulfide bonds is seen until the dose is greatly in excess (more than a factor of five) of the value at which damage appears in electron density maps derived from a scavenger-free crystal. In the electron density maps, ordered nitrate ions adjacent to the disulfide bonds are seen to lose an O atom, and appear to protect the disulfide bonds. In addition, results reinforcing previous reports on the effectiveness of ascorbate are presented. The mechanisms of action of both scavengers in the crystalline environment are elucidated
Description:Date Completed 16.08.2011
Date Revised 28.04.2011
published: Print-Electronic
Citation Status MEDLINE
ISSN:1600-5775
DOI:10.1107/S0909049511007163