Figure 3.
[2Fe-2S]2+ and [4Fe-4S]2+ clusters form in reaction mixtures involving SDUF under Catalytic conditions (Mössbauer experiment M2). (A and C) LC–ICP-MS (57Fe detection) of the mixture without and with 10 mM DTT, respectively. The HMWS, native SDUF, uncomplexed ISCU2, and LMWS eluted at ~9, 12, 16, and 28 mL, respectively. (B) Mössbauer spectrum (5 K, 0.05 T) of the sample without DTT. Green and blue lines are simulations of quadrupole doublets due to high-spin Fe2+ and [2Fe-2S]2+ clusters, respectively. The red line shows the overall simulation. (D) Mössbauer spectrum (5 K, 0.05 T, parallel) of the sample with DTT. Blue and gold lines are simulations of quadruple doublets due to [2Fe-2S]2+ and [4Fe-4S]2+ clusters, respectively. The red line shows the overall simulation.