Mössbauer and EPR detection of iron trafficking kinetics and possibly labile iron pools in whole Saccharomyces cerevisiae cells.

Autor: Delanoy G; Department of Chemistry, Texas A&M University, College Station, Texas, USA., Lupardus C; Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA., Vali SW; Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA., Wofford JD; Department of Chemistry, Texas A&M University, College Station, Texas, USA., Thorat S; Department of Computer Science and Engineering, Texas A&M University, College Station, Texas, USA., Lindahl PA; Department of Chemistry, Texas A&M University, College Station, Texas, USA; Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, USA. Electronic address: lindahl@chem.tamu.edu.
Jazyk: angličtina
Zdroj: The Journal of biological chemistry [J Biol Chem] 2024 Sep; Vol. 300 (9), pp. 107711. Date of Electronic Publication: 2024 Aug 22.
DOI: 10.1016/j.jbc.2024.107711
Abstrakt: The kinetics of iron trafficking in whole respiring Saccharomyces cerevisiae cells were investigated using Mössbauer and EPR spectroscopies. The Mössbauer-active isotope 57 Fe was added to cells growing under iron-limited conditions; cells were analyzed at different times post iron addition. Spectroscopic changes suggested that the added 57 Fe initially entered the labile iron pool, and then distributed to vacuoles and mitochondria. The first spectroscopic feature observed, ∼ 3 min after adding 57 Fe plus a 5 to 15 min processing dead time, was a quadrupole doublet typical of nonheme high-spin Fe II . This feature likely arose from labile Fe II pools in the cell. At later times (15-150 min), magnetic features due to S = 5/2 Fe III developed; these likely arose from Fe III in vacuoles. Corresponding EPR spectra were dominated by a g = 4.3 signal from the S = 5/2 Fe III ions that increased in intensity over time. Developing at a similar rate was a quadrupole doublet typical of S = 0 [Fe 4 S 4 ] 2+ clusters and low-spin Fe II hemes; such centers are mainly in mitochondria, cytosol, and nuclei. Development of these features was simulated using a published mathematical model, and simulations compared qualitatively well with observations. In the five sets of experiments presented, all spectroscopic features developed within the doubling time of the cells, implying that the detected iron trafficking species are physiologically relevant. These spectroscopy-based experiments allow the endogenous labile iron pool within growing cells to be detected without damaging or altering the pool, as definitely occurs using chelator-probe detection and possibly occurs using chromatographic separations.
Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article.
(Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: