Journal
JOURNAL OF INORGANIC BIOCHEMISTRY
Volume 220, Issue -, Pages -Publisher
ELSEVIER SCIENCE INC
DOI: 10.1016/j.jinorgbio.2021.111460
Keywords
Ferrozine; 2,2 ' bipyridine; 1,10 phenanthroline; Ferrous-ion complexes; MLCT; Absorption spectra; Iron chelators
Funding
- National Science Foundation, Division of Molecular and Cellular Biosciences (MCB) Award [1934666]
- Camille & Henry Dreyfus Foundation, Inc., The Henry Dreyfus Teacher-Scholar Award [TH-16-007]
- Direct For Biological Sciences
- Div Of Molecular and Cellular Bioscience [1934666] Funding Source: National Science Foundation
Ask authors/readers for more resources
Iron is a crucial nutrient for various forms of life. Chemical tools have been developed to detect reduced and oxidized forms of iron in biomolecules. This study utilized UV-vis spectrophotometry and chromogenic reagents to detect and quantify ferrous ions in aqueous solutions, revealing important kinetics and molar absorptivity values for different complexes.
Iron is an essential nutrient for virtually all forms of life. Because of its redox properties and involvement in a wide range of biological processes, a number of qualitative and quantitative chemical tools have been developed to detect reduced (Fe2+) and oxidized (Fe3+) forms of iron in biomolecules. These types of measurements are not only important in detecting iron species in solution, but also in understanding iron distribution, accumulation, and role in physiological and pathological processes. Here, we use UV-vis spectrophotometry and three common chromogenic reagents, ferrozine, 2,2'-bipyridine, and 1,10-phenanthroline to detect and quantify the concentration of ferrous ions in aqueous solutions, owing to the unique absorption spectra, specific molar absorptivity, and characteristic colors of these Fe2+-chelator complexes. Our results show that the kinetics of the formation of the {Fe2+-(ferrozine)(3)} complex, but not the{Fe2+-(bipyridine)(3)} or the {Fe(II)-(phenanthroline)(3)} complexes depend on the concentration of the iron chelator, requiring up to 20 min to complete when close to stoichiometric ratios are employed. The molar absorptivity values of these complexes under excess chelator concentrations were similar to 10% to 15% higher than reported literature values (i.e. 31,500 +/- 1500 M-1 cm(-1) for ferrozine at 562 nm, 9950 +/- 100 M-1 cm(-1) for 2,2'-bipyridine at 522 nm, and 12,450 +/- 370 M-1 cm(-1) for 1,10-phenanthroline at 510 nm). Our results have important implications when quantifying iron in biological systems and reveal optimal experimental conditions that must be employed for the accurate measurements of ferrous ions, whether free in solution, or after reduction of protein-bound ferric ions.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available