Fast proton-coupled electron transfer observed for a high-fidelity structural and functional [2Fe-2S] Rieske model.

ABSTRACT: Rieske cofactors have a [2Fe-2S] cluster with unique {His2Cys2} ligation and distinct Fe subsites. The histidine ligands are functionally relevant, since they allow for coupling of electron and proton transfer (PCET) during quinol oxidation in respiratory and photosynthetic ET chains. Here we present the highest fidelity synthetic analogue for the Rieske [2Fe-2S] cluster reported so far. This synthetic analogue 5(x-) emulates the heteroleptic {His2Cys2} ligation of the [2Fe-2S] core, and it also serves as a functional model that undergoes fast concerted proton and electron transfer (CPET) upon reaction of the mixed-valent (ferrous/ferric) protonated 5H(2-) with TEMPO. The thermodynamics of the PCET square scheme for 5(x-) have been determined, and three species (diferric 5(2-), protonated

SUBMITTER: Albers A 

PROVIDER: S-EPMC3985845 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature