Explain salting out of proteins.
Proteins have different solubilities in water. Certain amounts of water are required to solubilize the protein. So, to separate these proteins from one another, we introduce a highly soluble salt into the solution, such as ammonium sulfate, to cause the proteins to precipitate out one at a time. As AS begins to dissolve, water from the protein requiring the most water is being away by AS to solubilize it. As a result, this protein begins to precipitate, leaving the other two still soluble in solution