TY - JOUR
T1 - High Energy Resolution-X-ray Absorption Near Edge Structure Spectroscopy Reveals Zn Ligation in Whole Cell Bacteria
AU - Thomas, Sara A.
AU - Mishra, Bhoopesh
AU - Myneni, Satish Chandra Babu
N1 - Funding Information:
This work is supported by the National Science Foundation under grant EAR-1424899. The experiments were performed on beamline BM16 − UHD-FAME − at the European Synchrotron Radiation Facility (ESRF), Grenoble, France. The FAME-UHD project is financially supported by the French “grand emprunt” EquipEx (EcoX, ANR-10-EQPX-27-01), the CEA-CNRS CRG consortium, and the INSU CNRS institute. We are grateful for the beamline assistance of Dr. Olivier Proux at BM16. We also thank Professor Jeremy Fein for donating the bacterial strains used in this study as well as Dr. Emmanuel Doelsch for providing the XANES spectra of Zn3(PO4)2, Zn(acetate)2·2H2O, and Zn−phytate. We appreciate the assistance of Nicolas Slater with the ICP-MS measurements.
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/5/16
Y1 - 2019/5/16
N2 - Identifying the zinc (Zn) ligation and coordination environment in complex biological and environmental systems is crucial to understand the role of Zn as a biologically essential but sometimes toxic metal. Most studies on Zn coordination in biological or environmental samples rely on the extended X-ray absorption fine structure (EXAFS) region of a Zn K-edge X-ray absorption spectroscopy (XAS) spectrum. However, EXAFS analysis cannot identify unique nearest neighbors with similar atomic number (i.e., O versus N) and provides little information on Zn ligation. Herein, we demonstrate that high energy resolution-X-ray absorption near edge structure (HR-XANES) spectroscopy enables the direct determination of Zn ligation in whole cell bacteria, providing additional insights lost from EXAFS analysis at a fraction of the scan time and Zn concentration. HR-XANES is a relatively new technique that has improved our understanding of trace metals (e.g., Hg, Cu, and Ce) in dilute systems. This study is the first to show that HR-XANES can unambiguously detect Zn coordination to carboxyl, phosphoryl, imidazole, and/or thiol moieties in model microorganisms.
AB - Identifying the zinc (Zn) ligation and coordination environment in complex biological and environmental systems is crucial to understand the role of Zn as a biologically essential but sometimes toxic metal. Most studies on Zn coordination in biological or environmental samples rely on the extended X-ray absorption fine structure (EXAFS) region of a Zn K-edge X-ray absorption spectroscopy (XAS) spectrum. However, EXAFS analysis cannot identify unique nearest neighbors with similar atomic number (i.e., O versus N) and provides little information on Zn ligation. Herein, we demonstrate that high energy resolution-X-ray absorption near edge structure (HR-XANES) spectroscopy enables the direct determination of Zn ligation in whole cell bacteria, providing additional insights lost from EXAFS analysis at a fraction of the scan time and Zn concentration. HR-XANES is a relatively new technique that has improved our understanding of trace metals (e.g., Hg, Cu, and Ce) in dilute systems. This study is the first to show that HR-XANES can unambiguously detect Zn coordination to carboxyl, phosphoryl, imidazole, and/or thiol moieties in model microorganisms.
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U2 - 10.1021/acs.jpclett.9b01186
DO - 10.1021/acs.jpclett.9b01186
M3 - Article
C2 - 31039606
AN - SCOPUS:85065850351
SN - 1948-7185
VL - 10
SP - 2585
EP - 2592
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 10
ER -