The application of x-ray absorption spectroscopy to characterize metal centers in proteins

The availability of synchrotron radiation has transformed the status of X-ray absorption spectroscopy (XAS) from a topic of relatively minor interest to one of major scientific importance and activity. The availability of a continuum of electromagnetic radiation with a high intensity throughout a large part of the X-ray region has permitted reliable XAS data to be obtained for a wide range of elements. XAS is ideally suited to probe the immediate environment of specific atoms in a material, irrespective of its physical state.