[Precipitation of cytochromes c with complex cadmium iodide]

Using cytochrome c from horse heart and the yeast candida valida as examples, it was shown that a complex anion, cadmium tetraiodide (CdI42-), precipitated proteins from aqueous solutions at the reagent concentrations below 50 mM. The composition and pH value of the solution, as well as the starting protein concentration, considerably influenced the precipitation. The results suggest that this reagent acts on the protein by a mechanism similar to the salting-out process. The ability to act at small concentrations is the advantage of CdI42- over conventional agents.