Publication
Names
  • Sara A. Thomas
  • Bhoopesh Mishra
  • Satish C. B. Myneni
Title
High Energy Resolution-X-ray Absorption Near Edge Structure Spectroscopy Reveals Zn Ligation in Whole Cell Bacteria
Abstract
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.
Keywords
XANES, zinc, bacteria, XAS
Content
sample, spectral data, spectral data use
Year
2019
Journal
The Journal of Physical Chemistry Letters
Volume
10
Number
10
Pages
2585 - 2592
Document type
article
Publication state
published