The competition between chemistry and biology in assembling iron–sulfur derivatives. Molecular structures and electrochemistry. Part II. {[Fe2S2](SγCys)4} proteins

•We illustrate structure and electrochemistry of proteins containing {[Fe2S2](SγCys)4}core(s).•We present the structural changes consequent to Fe(III)/Fe(III)/Fe(III)Fe(II) passage in {[Fe2S2](SγCys)4} proteins.•We examine structure/electrochemistry of synthetic {[Fe2S2](S-X)4} complexes biomimetic of {[Fe2S2](SγCys)4} proteins.

Since iron–sulfur clusters are often involved in the electron transfer activity of redox active proteins, following our previous review on {Fe(SγCys)4}proteins (i.e. rubredoxins and related species; Coord. Chem. Rev. 257 (2013) 1777–1805), we focus here on molecular structures and electrochemistry of {[Fe2S2](SγCys)4}proteins (i.e. [2Fe-2S] ferredoxins). The present survey highlights the extended presence of such proteins in natural organisms such as bacteria, plants, fungi, algae, mammals and human parasites. In addition we put in evidence those structurally characterized [2Fe-2S] ferredoxins which have not yet received attention with respect to their redox activity, which is a fundamental aspect of their role in different biological processes. We will conclude with electrochemical and structural aspects of synthetic complexes possessing a [Fe2S2] core linked to four sulfur ligands in order to judge about their biomimetic reliability.

Graphical abstractRedox profiles of [2Fe-2S] ferredoxins of Mastigocladus laminosus and its truncated form.Figure optionsDownload full-size imageDownload high-quality image (121 K)Download as PowerPoint slide