title: Characterization of 3-iron ferredoxins by means of the linear electric field effect in EPR.
abstract: We describe a method for the differentiation of 3-iron from 2-iron and 4-iron Fe/S proteins based on consideration of both the magnetic field dependence of shifts in g induced by an externally applied electric field (LEFE) and the continuous wave EPR spectra properties. The magnetic field dependence and the magnitude of the LEFE for 3-iron ferredoxins are similar to those for 4-iron ferredoxins but differ considerably from those for 2-iron ferredoxins or for high potential iron proteins. Furthermore, as 3-iron ferredoxins and high potential iron proteins are EPR-active when oxidized while 2-iron and 4-iron ferredoxins are only EPR-active when reduced, the differentiation among all of them can be made on the basis of both continuous wave EPR and LEFE properties, but not by each individually.
mesh_terms: D000154:Aconitate Hydratase; D000818:Animals; D002417:Cattle; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D005288:Ferredoxins; D005970:Glutamate Synthase; D007501:Iron; D011487:Protein Conformation; D013045:Species Specificity; D013329:Structure-Activity Relationship
chemical_list: D005288:Ferredoxins; D007501:Iron; D005970:Glutamate Synthase; D000154:Aconitate Hydratase