Glutathione-complexed iron-sulfur clusters. Reaction intermediates and evidence for a template effect promoting assembly and stability.

Assembly and stabilization of a glutathione-complexed [2Fe-2S] cluster is promoted by aggregation of glutathione. The cluster core selects the tetramer species from a collection of equilibrating solution aggregate species, and in turn the core is stabilized toward hydrolytic degradation. Studies of glutathione derivatives, in combination with mass spectrometric and Mössbauer investigations provide insight on reaction intermediates during formation of [2Fe-2S](GS)4(2-).