DISCOVERY OF NOVEL IRON CLUSTERS IN PROTEINS BY MOSSBAUER-SPECTROSCOPY

Iron clusters are the catalytically active groups of many proteins. Th e basis building blocks of these clusters are few; they are all varian ts of three archetypal patterns: [Fe-O-Fe], [2Fe-2S], and [4Fe-4S]. Mo ssbauer spectroscopy, in conjunction with EPR spectroscopy, susceptome try and EXAFS, plays an important role in characterizing type, number, oxidation states and magnetic properties of such clusters in newly di scovered proteins, and in detecting how valency and magnetism vary by passing through the catalytical cycle of these proteins. In this contr ibution we present the characterization of a never iron cluster with u nusual bridging and terminal ligands and metal coordinations.