Biological EXAFS at 3rd Generation Sources: Is Brighter Better?

James Penner-Hahn,1,2 Tsu-Chien Weng,2 and Stephanie Gabelnik2

1Biophysics Research Division, University of Michigan, Ann Arbor, Michigan
2Department of Chemistry, University of Michigan, Ann Arbor, Michigan


Extended x-ray absorption fine structure (EXAFS) spectroscopy is one of the premier tools for investigating the local structural environment of metal ions. A key attraction is that EXAFS can be used to study any form of matter, and in particular that it can be used to study non-crystalline materials. For biological studies, the attractions of EXAFS are that it provides better accuracy than is typically possible from protein crystallography and that it can be used to interrogate protein states that cannot be crystallized. With the development of third generation synchrotron sources, the concentrations that can be studied by EXAFS, the sample volumes that are required for EXAFS, and the time required to measure an EXAFS spectrum have all decreased. At the same time, some of the experimental challenges associated with EXAFS (for example, radiation damage and sample heterogeneity) have been exacerbated. This talk will examine the impact of third-generation sources on biological studies with a view towards anticipating the likely impact of EXAFS on biology in the era of structural genomics.



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