title: XAS of dilute biological samples.
abstract: The experimental setup of beamline ID26 at ESRF (Grenoble) has been successfully exploited to obtain high-quality XAS (X-ray absorption spectroscopy) data from a biological sample where the metal concentration is about 100 micro M. The sample consists of the adenosine monophosphate deaminase (AMPD) histidine proline rich glycoprotein (HPRG) complex that contains 3-4 Zn(II) ions per dimer of approximately 320 kDa molecular weight. The experiment shows that third-generation X-ray sources equipped with insertion devices and appropriate optics and detectors allow the investigation of complex biological systems where the metal concentration is intrinsically low. The availability of such experimental setups makes possible a completely new set of experiments in biological XAS.
authors.affiliation: Department of Environmental and Human Sciences, University of Pisa, Via Roma 55, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Ranieri-Raggi
authors.forename: Antonio
authors.initials: A
authors.lastname: Raggi
authors.forename: Daniela
authors.initials: D
authors.lastname: Martini
authors.forename: Manuela
authors.initials: M
authors.lastname: Benvenuti
authors.forename: Stefano
authors.initials: S
authors.lastname: Mangani
mesh_terms: D000659:AMP Deaminase / Q000737:chemistry*; D015502:Absorptiometry, Photon / Q000379:methods; D008667:Metalloproteins / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D015032:Zinc / Q000032:analysis*; D000099053:Histidine-Rich Glycoprotein
chemical_list: D008667:Metalloproteins; D011506:Proteins; D000099053:Histidine-Rich Glycoprotein; D000659:AMP Deaminase; D015032:Zinc