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Publication Abstract from PubMed

Macromolecular crystallography (MX) and small-angle X-ray scattering (SAXS) studies on proteins at synchrotron light sources are commonly limited by the structural damage produced by the intense X-ray beam. Several effects, such as aggregation in protein solutions and global and site-specific damage in crystals, reduce the data quality or even introduce artefacts that can result in a biologically misguiding structure. One strategy to reduce these negative effects is the inclusion of an additive in the buffer solution to act as a free radical scavenger. Here the properties of uridine as a scavenger for both SAXS and MX experiments on lysozyme at room temperature are examined. In MX experiments, upon addition of uridine at 1 M, the critical dose D1/2 is increased by a factor of approximately 1.7, a value similar to that obtained in the presence of the most commonly used scavengers such as ascorbate and sodium nitrate. Other figures of merit to assess radiation damage show a similar trend. In SAXS experiments, the scavenging effect of 40 mM uridine is similar to that of 5% v/v glycerol, and greater than 2 mM DTT and 1 mM ascorbic acid. In all cases, the protective effect of uridine is proportional to its concentration.

Uridine as a new scavenger for synchrotron-based structural biology techniques.,Crosas E, Castellvi A, Crespo I, Fulla D, Gil-Ortiz F, Fuertes G, Kamma-Lorger CS, Malfois M, Aranda MA, Juanhuix J J Synchrotron Radiat. 2017 Jan 1;24(Pt 1):53-62. doi: 10.1107/S1600577516018452. , Epub 2017 Jan 1. PMID:28009546^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.