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

Since iron sulfur clusters are often involved in the electron transfer activity of redox active proteins, following our previous review on {Fe(S-Cys(gamma))(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](S-Cys(gamma))(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. (C) 2014 Elsevier B.V. All rights reserved.