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Treatment of Cells and Tissues with Chromate Maximizes Mitochondrial 2Fe2S EPR Signals. Int J Mol Sci 2019 Mar 06;20(5)



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Scopus ID

2-s2.0-85062628835   1 Citation


In a previous study on chromate toxicity, an increase in the 2Fe2S electron paramagnetic resonance (EPR) signal from mitochondria was found upon addition of chromate to human bronchial epithelial cells and bovine airway tissue ex vivo. This study was undertaken to show that a chromate-induced increase in the 2Fe2S EPR signal is a general phenomenon that can be used as a low-temperature EPR method to determine the maximum concentration of 2Fe2S centers in mitochondria. First, the low-temperature EPR method to determine the concentration of 2Fe2S clusters in cells and tissues is fully developed for other cells and tissues. The EPR signal for the 2Fe2S clusters N1b in Complex I and/or S1 in Complex II and the 2Fe2S cluster in xanthine oxidoreductase in rat liver tissue do not change in intensity because these clusters are already reduced; however, the EPR signals for N2, the terminal cluster in Complex I, and N4, the cluster preceding the terminal cluster, decrease upon adding chromate. More surprising to us, the EPR signals for N3, the cluster preceding the 2Fe2S cluster in Complex I, also decrease upon adding chromate. Moreover, this method is used to obtain the concentration of the 2Fe2S clusters in white blood cells where the 2Fe2S signal is mostly oxidized before treatment with chromate and becomes reduced and EPR detectable after treatment with chromate. The increase of the g = 1.94 2Fe2S EPR signal upon the addition of chromate can thus be used to obtain the relative steady-state concentration of the 2Fe2S clusters and steady-state concentration of Complex I and/or Complex II in mitochondria.

Author List

Antholine WE, Vasquez-Vivar J, Quirk BJ, Whelan HT, Wu PK, Park JI, Myers CR


Charles R. Myers PhD Professor in the Pharmacology and Toxicology department at Medical College of Wisconsin
Jong-In Park PhD Professor in the Biochemistry department at Medical College of Wisconsin
Jeannette M. Vasquez-Vivar PhD Professor in the Biophysics department at Medical College of Wisconsin
Harry T. Whelan MD Professor in the Neurology department at Medical College of Wisconsin
Pui Kei Wu PhD Instructor in the Biochemistry department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Cell Line, Tumor
Electron Spin Resonance Spectroscopy
Electron Transport Complex I
Electron Transport Complex II
Epithelial Cells
Xanthine Dehydrogenase
jenkins-FCD Prod-482 91ad8a360b6da540234915ea01ff80e38bfdb40a