Iron chemistry at the service of life

Abstract

Iron is an essential element for almost all organisms on Earth. It is necessary for a number of crucial processes such as hemoglobin and myoglobin transport and storage of oxygen in mammals; electron transfer support in a variety of iron-sulfur protein or cytochrome reactions; and activation and catalysis of reactions of a wide range of substrate like alkanes, olefins, and alcohols. Living organisms adopted iron as the main metal to carry out all of these functions due to the rich coordination chemistry of its two main redox states, Fe and Fe , and because of its abundance in the Earth's crust and oceans. This paper presents an overview of the coordination chemistry of iron that makes it suitable for a large variety of functions within biological systems. Despite iron's chemical advantages, organisms were forced to manage with some drawbacks: Fe insolubility and the formation of toxic radicals, especially the hydroxyl radical. Iron chemistry within biology is an example of how organisms evolved by creating molecular machinery to overcome these difficulties and perform crucial processes with extraordinary elegance and efficiency. © 2017 IUBMB Life, 69(6):382-388, 2017.

Regulation of lipid peroxidation and ferroptosis in diverse species

“…Iron and thiols are universal and necessary components of life (Toyokuni 2014;Berndt and Lillig 2017;Sanchez et al 2017). While phospholipids are components of all cell membranes, polyunsaturation is not an absolute requirement in all species, and archaea, bacteria, and fungi frequently contain poorly oxidizable saturated or monounsaturated lipid molecules (Suutari and Laakso 1994;Siliakus et al 2017).…”

Mimochrome, a metalloporphyrin‐based catalytic Swiss knife†

“…Nature has been able to bow kinetics and thermodynamics to make life not only possible but also predominant on Earth. We have learned, through the study of an exponentially growing number of biological structures, that this was accomplished by selecting only few elements [1][2][3][4], few molecules [5][6][7], and even few repetitive folding motifs [8][9][10][11][12][13]. This last aspect may appear surprising at a first glance, but it actually sounds pretty comfortable to chemists, who learned over centuries that the synthesis and/or functionalization of analogues from a starting framework moiety is advantageous and generally affordable, both in terms of synthetic pathway and economic cost.…”

Redox Balance Keepers and Possible Cell Functions Managed by Redox Homeostasis in Trypanosoma cruzi

“…However, these metals are redox active, and in an oxidative environment undergo redox-cycling reactions leading to exacerbated production of free radical species. The toxicity of iron, and, by association, of copper, is driven by their ability to reduce peroxides, via Fenton chemistry, into highly reactive hydroxyl radical that subsequently reacts at diffusion-limited rates with various biomolecules (Valko et al, 2016;Sánchez et al, 2017). Further, Fe-S clusters are preferred targets of O 2 • − , and their oxidation leads to Fe +2 release that then can feed Fenton reaction and ROS production (Fridovich, 1995).…”